JUUUUUUST one thing

[stvene3004]

The Luigi you added wasn't SMAS Luigi, it was SMA2 Luigi.

[stvene3004]

Also, how can I import the seperate Luigi graphics?

[rhelmot]

change the SEPERATEGFX variable to 1 in co-op.asm. That file contains all the knobs you can change to tweak the sprite's behavior.