I am a big fan of the Lore (and the Three Kingdoms equivalent version) as they can find a selection of the premium non-basics as well as providing the land untapped
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
The Fourth Doctor Im not sure Tom Baker here is all that great as a Simic commander, but this feels like an awesome card in a legends typal deck to me
You must still pay all costs and follow all normal timing rules when casting spells from among the cards in the booster pack
It helps preserve your valuable original cards from wear and tear, and it lets you test different strategies without sinking money into new singles
But unlike all the other shrines that just trigger and do stuff each turn, Shattered Heights does nothing if you cant pay the cost