<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:01a039a6-eab2-7c85-8082-ae653fe3c2e4,g:a42385e7-fb74-4609-bcf4-f21f8673f517-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:roleRef roleURI="http://imetrix.edgar-online.com/role/CoverPage" xlink:type="simple" xlink:href="sion-20261110.xsd#CoverPage"/>
  <link:presentationLink xlink:role="http://imetrix.edgar-online.com/role/CoverPage" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_CoverAbstract_01a039a6-eab3-7061-84de-a2ae8a6a9160" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_CoverAbstract"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag_01a039a6-eab3-727c-9b82-207ae2a7a8a1" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_AmendmentFlag"/>
    <link:presentationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_01a039a6-eab3-7061-84de-a2ae8a6a9160" xlink:to="loc_dei_AmendmentFlag_01a039a6-eab3-727c-9b82-207ae2a7a8a1" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey_01a039a6-eab3-7d87-9427-6ffe478b52c2" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityCentralIndexKey"/>
    <link:presentationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_01a039a6-eab3-7061-84de-a2ae8a6a9160" xlink:to="loc_dei_EntityCentralIndexKey_01a039a6-eab3-7d87-9427-6ffe478b52c2" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType_01a039a6-eab3-7642-b429-6e109f976917" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentType"/>
    <link:presentationArc order="3" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_01a039a6-eab3-7061-84de-a2ae8a6a9160" xlink:to="loc_dei_DocumentType_01a039a6-eab3-7642-b429-6e109f976917" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate_01a039a6-eab3-7371-b74d-52f8d9e70706" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentPeriodEndDate"/>
    <link:presentationArc order="4" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_01a039a6-eab3-7061-84de-a2ae8a6a9160" xlink:to="loc_dei_DocumentPeriodEndDate_01a039a6-eab3-7371-b74d-52f8d9e70706" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName_01a039a6-eab3-7e21-91c7-b7ca57c286a4" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityRegistrantName"/>
    <link:presentationArc order="5" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_01a039a6-eab3-7061-84de-a2ae8a6a9160" xlink:to="loc_dei_EntityRegistrantName_01a039a6-eab3-7e21-91c7-b7ca57c286a4" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationStateCountryCode_01a039a6-eab3-794e-a5ae-a3ddb04bf0d9" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityIncorporationStateCountryCode"/>
    <link:presentationArc order="6" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_01a039a6-eab3-7061-84de-a2ae8a6a9160" xlink:to="loc_dei_EntityIncorporationStateCountryCode_01a039a6-eab3-794e-a5ae-a3ddb04bf0d9" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber_01a039a6-eab3-767d-a806-bc87e00b494f" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityFileNumber"/>
    <link:presentationArc order="7" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_01a039a6-eab3-7061-84de-a2ae8a6a9160" xlink:to="loc_dei_EntityFileNumber_01a039a6-eab3-767d-a806-bc87e00b494f" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_01a039a6-eab3-75cf-b896-3d1b29a99893" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityTaxIdentificationNumber"/>
    <link:presentationArc order="8" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_01a039a6-eab3-7061-84de-a2ae8a6a9160" xlink:to="loc_dei_EntityTaxIdentificationNumber_01a039a6-eab3-75cf-b896-3d1b29a99893" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine1_01a039a6-eab3-789d-9279-82c5ac489266" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressAddressLine1"/>
    <link:presentationArc order="9" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_01a039a6-eab3-7061-84de-a2ae8a6a9160" xlink:to="loc_dei_EntityAddressAddressLine1_01a039a6-eab3-789d-9279-82c5ac489266" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown_01a039a6-eab3-7614-b9ff-3dc2357c105a" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressCityOrTown"/>
    <link:presentationArc order="10" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_01a039a6-eab3-7061-84de-a2ae8a6a9160" xlink:to="loc_dei_EntityAddressCityOrTown_01a039a6-eab3-7614-b9ff-3dc2357c105a" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressStateOrProvince_01a039a6-eab3-75be-80a2-89bbcbc4e08e" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressStateOrProvince"/>
    <link:presentationArc order="11" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_01a039a6-eab3-7061-84de-a2ae8a6a9160" xlink:to="loc_dei_EntityAddressStateOrProvince_01a039a6-eab3-75be-80a2-89bbcbc4e08e" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode_01a039a6-eab3-724a-9849-413713fc0ef8" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressPostalZipCode"/>
    <link:presentationArc order="12" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_01a039a6-eab3-7061-84de-a2ae8a6a9160" xlink:to="loc_dei_EntityAddressPostalZipCode_01a039a6-eab3-724a-9849-413713fc0ef8" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CityAreaCode_01a039a6-eab3-75d2-8de5-8117e1af1d1e" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_CityAreaCode"/>
    <link:presentationArc order="13" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_01a039a6-eab3-7061-84de-a2ae8a6a9160" xlink:to="loc_dei_CityAreaCode_01a039a6-eab3-75d2-8de5-8117e1af1d1e" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber_01a039a6-eab3-76a9-9f5f-d695daf02714" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LocalPhoneNumber"/>
    <link:presentationArc order="14" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_01a039a6-eab3-7061-84de-a2ae8a6a9160" xlink:to="loc_dei_LocalPhoneNumber_01a039a6-eab3-76a9-9f5f-d695daf02714" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_WrittenCommunications_01a039a6-eab3-7a42-8b2d-c08fd68193c6" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_WrittenCommunications"/>
    <link:presentationArc order="15" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_01a039a6-eab3-7061-84de-a2ae8a6a9160" xlink:to="loc_dei_WrittenCommunications_01a039a6-eab3-7a42-8b2d-c08fd68193c6" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SolicitingMaterial_01a039a6-eab3-7720-a9da-943e4b435629" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_SolicitingMaterial"/>
    <link:presentationArc order="16" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_01a039a6-eab3-7061-84de-a2ae8a6a9160" xlink:to="loc_dei_SolicitingMaterial_01a039a6-eab3-7720-a9da-943e4b435629" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_PreCommencementTenderOffer_01a039a6-eab3-7743-8b4c-9df8cf6f7336" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_PreCommencementTenderOffer"/>
    <link:presentationArc order="17" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_01a039a6-eab3-7061-84de-a2ae8a6a9160" xlink:to="loc_dei_PreCommencementTenderOffer_01a039a6-eab3-7743-8b4c-9df8cf6f7336" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_PreCommencementIssuerTenderOffer_01a039a6-eab3-7de8-bb45-0b434b90dac7" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_PreCommencementIssuerTenderOffer"/>
    <link:presentationArc order="18" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_01a039a6-eab3-7061-84de-a2ae8a6a9160" xlink:to="loc_dei_PreCommencementIssuerTenderOffer_01a039a6-eab3-7de8-bb45-0b434b90dac7" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle_01a039a6-eab3-7597-be4b-b711a4a9ce7e" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_Security12bTitle"/>
    <link:presentationArc order="19" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_01a039a6-eab3-7061-84de-a2ae8a6a9160" xlink:to="loc_dei_Security12bTitle_01a039a6-eab3-7597-be4b-b711a4a9ce7e" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol_01a039a6-eab3-7883-849b-7704da33df21" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_TradingSymbol"/>
    <link:presentationArc order="20" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_01a039a6-eab3-7061-84de-a2ae8a6a9160" xlink:to="loc_dei_TradingSymbol_01a039a6-eab3-7883-849b-7704da33df21" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName_01a039a6-eab3-75ed-b200-92b5fb8b4242" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_SecurityExchangeName"/>
    <link:presentationArc order="21" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_01a039a6-eab3-7061-84de-a2ae8a6a9160" xlink:to="loc_dei_SecurityExchangeName_01a039a6-eab3-75ed-b200-92b5fb8b4242" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany_01a039a6-eab3-7398-b0bf-dc977b4190fa" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityEmergingGrowthCompany"/>
    <link:presentationArc order="22" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_01a039a6-eab3-7061-84de-a2ae8a6a9160" xlink:to="loc_dei_EntityEmergingGrowthCompany_01a039a6-eab3-7398-b0bf-dc977b4190fa" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityExTransitionPeriod_01a039a6-eab3-7d88-b71d-35118a3e24ed" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityExTransitionPeriod"/>
    <link:presentationArc order="23" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_01a039a6-eab3-7061-84de-a2ae8a6a9160" xlink:to="loc_dei_EntityExTransitionPeriod_01a039a6-eab3-7d88-b71d-35118a3e24ed" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </link:presentationLink>
</link:linkbase>
