Anytime Umbris, or another Nightmare or Horror creature enters the battlefield under your control, you get to exile cards from the top of their deck until they hit a land card
Rassilon, the War President Rassilon, the War President reminds me of Phyrexian Arena, as both deal damage to you at the beginning of your upkeep in exchange for value
Jace, the Living Guildpact Considering a planeswalker for their ultimate is always dubious, as it takes time to reach it and your opponents have ample tools to stop themmore than ever as cards like Get Lost that directly destroy planeswalkers are printed
Pre-release community estimates placed this at $200-400 raw, with the card positioned to settle north of $300 as supply stabilises
Power Conduit exists, after all
cards on your field is equal to or less than the number on your opponent's field, choose one: K type, play up to 1 [Vinsmoke Yonji] with a cost of 4 from your hand or trash