Of those thousands, there are a few hundred cards that have unique effects that happens at a particular situation
Thassa, God of the Sea seems like it would be great in a go-wide merfolk deck, and it does have a place there because its activated ability helps with Coastal Piracy types of effects
I like shenanigans involving other peoples creatures, especially if Im the one causing them and I can interact at instant speed
Katara, Water Tribes Hope Katara, Water Tribes Hope wants to go wide with a bunch of creatures and use her Waterbending payoff to swing for tons of damage
Yeah, there is no way that The Darkness CrystalThe Darkness Crystal isn't number one on the list
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