Mercy Killing in particular seems good with many of the strategies we can pepper into our deck, giving Drizzt a death trigger and giving us a bunch of Elf tokens too, all at instant speed
2021-03-19 If the last card exiled is a card with an Adventure, you may only cast the spell as an Adventure if that spell has a lesser mana cost than the spell with cascade
This leaves the deck with a curve of something like suspend Lotus Bloom on Turn 1, cast some cantrips on Turn 2, on Turn 3 play a Phyrexian Unlife, on Turn 4 cast Glorious End on the opponent's upkeep to force them to skip their turn, and on Turn 5 win the game
Crew 3 (Tap any number of creatures you control with total power 3 or more: This Vehicle becomes an artifact creature until end of turn.) After the first ability has resolved targeting a creature, that creature has lifelink and can't be blocked for the rest of the turn, even if its power increases to 3 or greater
It's hard to count on them to be on the battlefield all the time, which makes decks that rely on their commander inconsistent