At the time, I didn't have any Heart Scales to teach it Ancient Power. I also wanted to beat the Elite Four with only Johto Pokemon. Also, Mamoswine is kind of ugly. Regardless, I'll probably get around to evolving it soon. I leveled my party up to about Lv. 42 before getting impatient and taking on the E4. I did pretty well up until Lance... By the end of the battle, Feraligator and Piloswine were in the red and were my only Pokemon left when I took down Lance's Charizard and emerged victorious.