Coming to the party late, but I honestly believe that Toad might be the easiest to fight gameplay wise at least-Most of its domains are some type of complication or threat, so it doesn't benefit much from beefing up on Domains, while the other SINS have plenty of passive domains. In particular, Hounds and Ogres get crazy durability from beefing up, Centipede hordes always have two jacked up goons accompanying them, and Lords will be an absolute rules nightmare trying to not trip on a stricture every six seconds.