Riot, the best metaknight in tx is Dojo. stiltz is a close 2nd. Metaknights CANNOT escape the grab release to f-air if the marth does it right.
Against DDD, its hard. DDD can chain grab you at will and can do 16% damage from a single back throw...so how do you win?
If you space correctly, he will not be able to grab you. he may be able to jab but its far better than being CGed. Also, PLEASE use marths dancing blade. this is free damage once you connect with it becuase he cannot smash DI good enogh to escape it.
AND!
The SMASH BACK ROOM has released thier new rules about 2 weeks ago. PLEASE view them!
I bring that up because if you STILL get CG alot from ddd....i recommend you pick norfair as a CP stage. He will be able to CG you only 3 times AT MOST. Consider things like this becuase the ONLY thing that worries people about ddd is the CG....if you hinder that abilit....ddd is MUCH more possible to beat without poopin your pants.