He went marth. He wasn't sandbagging, but I think he had a fear of corneria as ganon (PC at RoM?) After the third game, simna goes, "You're cheap," and kage responds "What?! You're cheap!!!"
Edit -- Simna's strategy on corneria is basically to get a lead and then camp indefinitely under the gun. Most characters have a really hard time approaching him there. Although, since this chart is based on the new rule set I guess this strategy is gone.
Marth >>> Ness, and I disagree with whoever said ICs > Ness. He has some tricks (Nana can't DI out of pk fire), but they're not especially practical. He has a hard time separating them, because the moves that are strong enough are either slow and punishable, or point blank and punishable. A lot of different grab combos work on him due to his slow second jump, and u-smash kills him early. Aside from that, ICs don't have trouble edgeguarding him (just jump off and b-air, edgehog or smash), outrange and outmaneuver him, and combo him without grabs extremely easily (again, his second jump).