Luigi's Counter Picks

For most characters, if you down tilt around 90%, it puts the opponent into an automatic tech chase. More likely than not, they will miss the tech, which leads to a guaranteed jab-lock.

All I have to say against any of the weak opponents above is, jump cancel x2 with a down air In between then up B.

Go for jablocks to get an early kill.

For Luigi: Plunger combos into down air off stage at mid to high percent. It's usually best to fast fall the zair so you have maximum time to get the dair

I main him, so I think that you should punish up -b landings on stage with super jump punch or if you're not confident enough, you should use cyclone or grab.