No 10, so these will do: Egg Emperor (Generations 3DS): Just too easy, and can get annoying, if you aren't prepared. Final Tails Vs Eggman (Adventure 2): Ridiculously hard, especially for Tails, as Eggman takes less damage due to the Protection Armour. Zavok (3DS Lost World; Hard Mode only): Just personally don't like this boss, especially in Hard Mode; 1 ring, hard-to-dodge attacks, and Zavok...