When Kaalia enters, look at the top six cards of your library. You may reveal an Angel card, a Demon card, and/or a Dragon card from among them and put them into your hand. Put the rest on the bottom of your library in a random order.
Cast Kaalia early as a flying, vigilant card-advantage engine that digs for your best Angels, Demons, and Dragons every time she enters. Flood the board with powerful fatties through cheating and ramp, then close games with evasive beatdown and high-impact ETB or attack triggers. Keep replaying her via blink or recursion to refill your hand all game.
Provides repeatable, color-fixed card advantage that refills your hand with bombs every cast
Cheap three-mana commander that's hard to remove tax with and easy to recast
Flying and vigilance let her attack and still defend
Mardu colors give access to the best removal, ramp, and reanimation
Selection whiffs if your top six lacks an Angel, Demon, or Dragon — tribal density matters
Does not cheat creatures into play herself (unlike the original Kaalia of the Vast), so you still pay full price
Reliant on expensive top-end that can clog your hand without ramp or cheat effects
Vulnerable to board wipes and graveyard hate against your reanimation plan