[+2]: You gain 1 life for each creature you control. [–3]: Creatures you control get +2/+2 until end of turn. [–9]: Put X +1/+1 counters on target creature, where X is your life total.
2018-07-13
Ajani's second ability affects only creatures you control at the time it resolves. Creatures you begin to control later in the turn won't get +2/+2.
2018-07-13
The value of X is determined only as Ajani's third ability resolves. If your life total changes later, the creature won't gain or lose +1/+1 counters.