Boney for the win!!!!

(sarcasm)
for the third one I dont know, Kumatora only has Starstorm and Ground for PKs and maybe Paralysis/Hypnosis/Brainshow and Power Downs. It wouldnt feel Kumatora to me, LUcas has all of her moves (most of them).
As for Duster, Lucas having Rope-Snake kinda kills his chances, unless he is based on his Thief tools, but the dont have any offensive ability, maybe throwing electric-balls thingys?..., mmm, Pokey doesnt fight, unless he is riding his spider-mech, which is too big, and this too-big excuse cannot be ignored becouse if you make the spider mech smaller, it would make Pokey smaller, making Pokey like half the size of Lucas in Brawl so that the Spider mech size is similar to bowser's, maybe a little bigger.
mmm...no Mother 3 characters left (that actually have a chance)...Lucas and Claus are just fine by themselves ^^
(As I said before, I dont see Flint with a original and good moveset, so I'm not counting him unless I hear a good one)
and no, Duster doesnt use PSI