Partner with Gatriel, Sliver Sword (When this creature enters the battlefield, target player may put Gatriel into their hand from their library, then shuffle.)

Defender, flying

Whenever a creature enters the battlefield under your control, put X +1/+1 counters on it and X +1/+1 counters on Sofiel, Golden Shield, where X is the number of creatures you control with toughness 4 or higher. Sofiel, Golden Shield can block an additional creature each combat for each +1/+1 counter on her.