I never won with a shield build. Seal, hangman, and the item that makes ties wins gave me a guaranteed win. I think these items are the best as they make the fights actually consistant. When I fought final enemy, I would just shred them while barely taking damage since I would win all contest . It feels like the enemies quickly out-scale the player so one can only win with good luck and getting good upgrades, while some upgrades like the dagger (which I don't even know what it does) or the flurry (which suffers from it's one time use) are just not good enough where rolling them greatly decreases your chance of winning.