It doesn't lose it as the turn ends or if another player gains control of it
Sliver Support There are a handful of cards that directly support Slivers, and then there are a bunch of cards that can support decks that have a heavily focused tribal theme: Hive Stirrings, Hivestone, Sliversmith, Cavern of Souls, Cover of Darkness, Kondas Banner, Packs Disdain, Shared Triumph, Standardize, Steeling Resolve, Unnatural Selection, Adaptive Automaton, Alpha Status, Descendants Path, Faces of the Past, Harsh Mercy, Luminescent Rain, Shared Animosity, Urzas Incubator, Call to the Kindred, Distant Melody, Door of Destinies, Mana Echoes, Riptide Replicator, Roar of the Crowd, Belbes Portal, Coat of Arms, Cryptic Gateway, Patriarchs Bidding, Vigean Intuition Changelings Lets also not forget that Lorwyns changelings are Slivers too
34/102 Machoke
Even with the bigger deck sizes of Commander, you should only need about 20 legends in your deck to hit something reliably