Vigilance, haste Kelsien gets +1/+1 for each experience counter you have. {T}: Kelsien deals 1 damage to target creature you don't control. When that creature dies this turn, you get an experience counter.

Minthara has ward {X}, where X is the number of experience counters you have. At the beginning of your end step, if a permanent you controlled left the battlefield this turn, you get an experience counter. Creatures you control get +1/+0 for each experience counter you have.

Double strike, vigilance Whenever you cast a creature spell with mana value 5 or greater, you get an experience counter. Kalemne gets +1/+1 for each experience counter you have.

Flying, lifelink, haste Whenever Otharri attacks, you get an experience counter. Then create a 2/2 red Rebel creature token that's tapped and attacking for each experience counter you have. {2}{R}{W}, Tap an untapped Rebel you control: Return this card from your graveyard to the battlefield tapped.