Vishgraz, the Doomhive is the more explosive, scarier commander option: he's a 5-drop so he costs more but he enters the battlefield with four toxic 1 creatures, essentially double the amount of poison per combat than Ixhel, and he can grow into a big threat as the game progresses
The great part about this one is that it doesnt have a cost limit on the instant, only that it be an instant and be currently in your graveyard
Tender Tambow is also an important part of the set, because it represents, yes, a cycle of big-mana payouts that have an early game way to stabilise and advance your mana
These two decks can take a player from having no collection at all to playing a game of Commander in just moments
They'll be available to buy in separate booster packs in the MTG Arena digital store, next door to the regular Innistrad: Crimson Vow boosters