Mewtwo vs Joker
Matchup Tips and Strategies
In the matchup against Joker, leverage Mewtwo’s aerial attacks to pressure him off-stage, particularly using N-air to exploit his vulnerable recovery with Grappling Hook. When Joker activates Arsene, utilize Forward Throw to chip away at his Rebellion Gauge, shortening his time with the powerful ally. Be mindful of Joker's Down-B and use Side-B to interrupt his counter, keeping him on the defensive. As Joker approaches kill percent, look for opportunities to set up your kill confirm with Confusion followed by F-air, ensuring you capitalize on his vulnerabilities, especially when he's above 138%, where he becomes much easier to finish off.
Tips for Mewtwo vs Joker
Joker's base recovery (Grappling Hook) is very susceptible to Mewtwo's ariel attacks, especially N-air (Body Spark); Whenever it's possible, use your ariels to pressure Joker off-stage.
[While Arsene is active] Mewtwo's Foward Throw (Shadow Cannon) is a good tool to chip away at the Rebellion Gauge. If you want to shorten Arsene's screen-time, abuse this throw!
Whenever Joker decides to abuse his Down-B (Rebel's Guard/Tetrakarn/Makarakarn), use Mewtwo's Side-B (Confusion) to interrupt Joker out of the armor/counter.
Mewtwo's Signature Kill Confirm (Confusion [Command Grab] + F-air) can
reliably kill Joker starting at 124% [Mid FD/DI'd], 114% [Side FD/DI'd], and 150% [Full FD/Correct DI]
A general rule of thumb: >138% = A Dead Joker; He cannot survive B/U-Throw, F-Tilt, Any Smash attack, F-air, and B-air.