things ness can reflect (regarding megaman)
fsmash, leafshield (down-b?) when thrown, that sticky bomb (side-b?), metal blades (neutral-b?), jab projectiles (it is like jab, dashattack and nair right?)
I'm not sure about uair and dair, if you're able to reflect it, then it should still fly in its normal pattern (up uair, down dair obviously)
but megaman could get hit by that in theory (but it won't hit him unless someone else kicks him into it fast enough)
you could test that with friendly fire off and a teammate
if it can hit the teammate, then the move is reflected, but since it can't hit megaman, and it can hit teammates regardless of that with friendly fire on, this shouldn't help you anyway