Trainer Cards Play Trainer cards (as many as you want, but only one Supporter card and one Stadium card per turn)
If a player is able to swing in with even one or two creatures of these types, Spawning Kraken can create an incredible offensive force that can cumulatively grow larger and larger as a player gains additional Krakens
Or you could simply substitute those three to eight dual lands with any number of cheaper alternatives for the time being
So, even if Proxy King is legit and the cards look great, that does not make them legal for sanctioned tournaments
See examples in Evolving Wilds, Misty Rainforest and Boros Garrison
Enchantments The enchantments support the mechanics already touched on with the creatures: Shiny Impetus creates a goaded creature and generates treasure tokens, the Warlock Class makes opponents lose life points as well as draw cards for ourselves and the Dead Mans Chest is in a similar vein as Gonti and Daredevil