The guy above this is a professional dumbas.
Anyway to do that transparent effect you need to make a think frame like:
addHook("ThinkFrame", do for player in players.iterate() player.mo. frame = $|FF_TRANS30 end end)
If you want to make like Crystal Sonic then use player.mo.blendmode = AST_ADD and it should do it.(I can help when you ask but later because it's late and I'm on phone, I hope I helped)