This is random and might be over the place so let's just get this overwith.

Ult:

Increase duration and/or add a movement speed buff. Better entry potential.
Make the ult indicator like a Yoru Gatecrash. Can only be seen when close.
When Phoenix returns back to his ult position, a small to medium sized AoE around him explodes dealing damage the closer you are to it. Might solve the issue where people camp his ult position just to knife him.

C:

Either make it longer, last longer, or deal more damage. I think it's fine as it is not gonna lie.

Q:

Make the flash last longer/pop faster. (RIP to your teammates' eyes lmao)

E:

Larger AoE, more damage, another charge (for a price of course). Anything's fine.

I just want Phoenix buffs man.