The Blue Spirit

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)

Creatures you control have "Whenever one or more counters are put on this creature for the first time each turn, draw a card."

The first face-down creature spell you cast each turn costs less to cast.

Whenever a face-down creature you control enters, draw a card.

Whenever you cast a spell during your turn other than your first spell that turn, create a 2/2 blue and black Zombie Rogue creature token.

Whenever a Zombie you control enters, put a +1/+1 counter on it for each other Zombie that entered the battlefield under your control this turn.

Firebending 2 (Whenever this creature attacks, add . This mana lasts until end of combat.)

When Azula enters, target opponent exiles a nontoken creature they control, then they exile a nonland card from their graveyard.

During your turn, you may cast cards exiled with Azula and you may cast them as though they had flash. Mana of any type can be spent to cast those spells.

As long as Kianne's power is even, you may cast noncreature spells as though they had flash.

As long as Kianne's power is odd, you may cast creature spells as though they had flash.

Whenever you draw a card, put a +1/+1 counter on Kianne.

Flying

When this creature enters, draw a card if you've cast another blue spell this turn.