They will move directly from the end of combat step of one combat phase to the beginning of combat step of the next one
Another trick you can use to sniff out potentially busted planeswalkers simply in terms of mana advantage are those with +loyalty abilities which are on point mana wise but scale nicely with planeswalkers
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
For analysis of more cards the generator created, read this other companion article
Even the lesser holos like Blastoise and Venusaur in PSA 10 can sell for incredible profits
Its not rare, but the games RNG had been mocking me
