Ummm... let's check the logic here. EVERYONE is unbeatable because of some characteristic they have when a seasoned player is using them.
Oh, and Maxi has easy combos yes, but nothing that a seasoned player can't avoid. Maxi has incredibly awesome combos that are harder to do and more complex that no seasoned player can beat when another seasoned player is using him.
Necrid is way out of whack. There was a Soul Calibur 2 competition in the mall here in Houston, and people WERE NOT ALLOWED to use Necrid, he's fast, extremely power and his hand can be a long range or short range weapon.
Also, I've played MANY people. MANY, and Makasuro is the only guy who can beat me, and even me and him go round for round, match for match. When I say we played that game religiously, I mean it in the most sad, pathetic, geeky, nerdy way you can think of.