Phoenix Cannon is a T-Spin Single (only possible in TETR.IO) -> T-Spin Double -> FinT Cannon opener by ponix1.

First Bag

180° T-spin Single (TETR.IO only)

Second Bag

This bag is not 100%. If possible, it can be built in any of these ways depending on the queue.

Third Bag

This bag can be built in any of these ways.

Z in hold

Z in hold

For the small chance that none of those are possible, these can be built. This isn't ideal though because for the next Z piece to spin under the I piece, the wall kick (where the O piece is) must be 1 mino higher.

Fourth Bag

This bag can be built in any way.

Alternate Path

This is an alternate path starting from the third bag that goes Incomplete T-Spin Triple -> T-Spin Double -> Incomplete T-Spin Triple -> T-Spin Double -> STSD.