Black Widow, Daring Operative Though costly, Black Widow, Daring Operative has excellent scaling with its saboteur trigger
Celes, Rune Knight puts +1/+1 counters on creatures when they enter from the graveyard, which makes it great with any Persist creatures in her color combination
Using Lilianas -4 ability right away can also be quite useful if the opponent is ahead on board
You may turn this conspiracy face up any time and reveal that name.) Whenever you cast an instant or sorcery spell with the chosen name, you may draw a card
However, its in Arthurs ability that he truly shines: when played, he can give a chosen character Challenger +2 and Resist +2 (that means they get +2 Strength while Challenging and a reduction of 2 damage thats being dealt to them), plus they can also challenge Ready, not Exerted, characters on the same turn too