To 2HKO standard Ferrothorn without LO you need at least 285 SAtk. With a negative nature that would require at least base 141: Chandelure, Kyogre outside of rain, Rayquaza, Dialga, Palkia, Reshiram, Kyurem-W, Mewtwo, Deoxys and Deoxys-A. HP Fire is a waste on Kyogre and everything but Deoxys has stronger Fire moves.
Edit: Forgot Darmanitan-Z, but Tobes said it shouldn't be mendioned. Will I get infracted for that?
To 2HKO physically defensive Latias with HP Ice after SR you need at least 494 SAtk. Due the restrictions of the game to 16 bit the maximum hackable base stat would be 255, equal to 491 SAtk. In theory, you need base 257 to reach such a level. But as said, the maximum possible base stat is 255 due limitations.
Simple, isn't it?
Last edited by Onicon; Feb 15th, 2013 at 10:19:49 AM.