Kumena, Hakbal, Svyelun, plus the lords and draw engines every Merfolk EDH deck wants.
In Merens case you can reanimate creatures of larger and larger mana value as the game progresses
For big stompy decks that make a lot of mana, this is a wild 2-for-1, especially as you can really customize how much damage youre dealing
I'm using my standard land cut here
Any power- or toughness-setting effects that start to apply to a creature after Octopus Umbra becomes attached to it will overwrite this effect
As a new collector, the cards I found were just okay at best, but I would understand the value of this box if I also had absolutely no exposure to magic, but I did passively follow the scene so I found the collection to be a bit disappointing