Dawnbreaker + Phoenix

Why this works

Dropping a Supernova in the middle of a fight is a huge commitment for Phoenix, often baiting the entire enemy team to focus it down. This is where Dawnbreaker provides perfect cover. She can cast Solar Guardian directly on the Supernova from anywhere on the map. Her arrival stuns and damages anyone trying to attack the egg, buying crucial time. Dawnbreaker is a durable frontliner who can then stand her ground and fight, making it incredibly difficult for opponents to deal enough damage before the Supernova explodes. It turns a vulnerable moment for Phoenix into a massive teamfight advantage.

The global combination lets the pair dictate the pace of the mid-game. Phoenix can initiate aggressively, confident that backup is always available. Enemies are forced into a lose-lose: either commit resources to killing the egg through Dawnbreaker's protection and likely die, or scatter and give up the objective while still getting hit by the stun. The main counterplay is to have overwhelming burst to destroy the egg before Solar Guardian lands, or to try and catch Phoenix with chain stuns before he can even cast his ultimate. Otherwise, they're always fighting on your terms.