If you have them, consider adding any of these cards in place of some of the less-efficient dual lands or even basic Swamps or Plains: Shadowy Backstreet, Concealed Courtyard, Isolated Chapel, Brightclimb Pathway/Grimclimb Pathway, Godless Shrine
allows you to play more than one land a turn
Two creatures specifically, BloodthirsterBloodthirster and Port RazerPort Razer, are exactly what we want for more and more combat steps
Slinn Voda, the Rising Deep While its one of the few commanders to mention the full suite of KLOS sea creatures, Slinn Voda, the Rising Deep is more of a support player in my eyes
The card's ability allows players to ready a chosen character of theirs a second time to either challenge an opponent or protect themselves from challenges