Impassioned Orator

Whenever another creature enters the battlefield under your control, you gain 1 life.

Leonin Vanguard

At the beginning of combat on your turn, if you control three or more creatures, Leonin Vanguard gets +1/+1 until end of turn and you gain 1 life.

Target creature gets +2/+2 and gains flying until end of turn. You gain 2 life.

Whenever a creature enters the battlefield under your control, you gain 1 life.

Whenever you gain life, put a +1/+1 counter on Ajani's Pridemate.

Target creature gets +2/+2 and gains lifelink until end of turn. (Damage dealt by the creature also causes its controller to gain that much life.)

Target creature gets +2/+2 until end of turn.
Addendum — If you cast this spell during your main phase, that creature gains flying until end of turn.

Enchant creature
Enchanted creature can't block, and its activated abilities can't be activated.