Dom Harvey
Contributor
I haven't tried Narset but I'm pushing library manipulation, spells matter in Jeskai colours, and I've always loved Chandra, the Firebrand, so maybe I should.
I'll put my vote in for Ajani, Caller of the Pride. A 3-mana, 5-loyalty planeswalker is so tough to deal with, especially when you're pumping a 2-drop and putting them on the back foot; you get into ultimate territory much more often than you'd think, which forces them to contort their plays even further to get it off the board. The -3 just kills people out of nowhere at virtually any stage of the game and ensures your aggro deck always has late-game outs.