Nezahal, Primal Tide Nezahal, Primal Tide is uncounterable and gives you an infinite hand size, but it seems that its designed to keep Nezahal alive
Gogo, Master of Mimicry is a great, bizarre choice
You can also abuse infinite combos, which makes The Gitrog Monster a viable combo deck in cEDH
While this Ajani's -3 helps decks trying to go wide, providing each of your creatures with +2/+2, its ultimate -9 ability provides further payoff for the lifegain of its +2, putting a number of +1/+1 counters on a creature equal to your life total
Instead, look for build-around cards like Dread Presence, Empyrean Eagle, Gnarlback Rhino, or cards with traits you know you'll use like removal and cheap ramp (examples: Chandra's Outrage, or Leafkin Druid)