Now for some replies...
Neo_Fire_Sonic: If you think Masamune is ridiculous, wait till you see Mouri, Oda, Hideyoshi, and Honda.
Win: Rei's Sengoku Basara characters have some crazy infinite spamming. I thought it was hilarious, but I can see where people would get frustrated fighting them. As for the three round fights, that's just something I did to make the Semi-finals and finals longer. I probably should've mentioned it then.
Hyoudou: I have defeated Date Masamune. I haven't fought Rei's characters myself, but I suspect they'd be very frustrating.