For this archetype, your heavy hitters are going to be Evolving Adaptive , which gets bigger and bigger with each oil counter on it, Kuldotha Cackler , whose power increases the more permanents you control with oil counters on them, and Evolved Spinoderm, a big, hard-hitting creature that can be difficult to remove as long as you keep more than two oil counters on it
Record: 1-3 While hitting Diamond 4 was cute, the egregious tenth draft left me scorned
The real power is likely to be the cards activated ability, which costs X to activate and reads: Exile Karns Sylex: Destroy each nonland permanent with mana value X or less
You can also pay three mana, tap it, and pay X energy to draw X cards
This item card does have its uses in blocking out your opponent from putting in new, useful Pokemon on the bench, but that's not a good enough reason to run this card instead of a better one in your deck
Consider its card type, any effects that modify when you could cast it (such as flash) and any other effects that stop you from casting it (such as from Meddling Mages ability) to determine if and when you can do this