While Skrelv isnt a particularly powerful attacker, and nor can it block anything at all, it does have a powerful ability that could help it see play in decks even if theyre not trying to poison out their opponents
Whenever you cast a noncreature spell, put three +1/+1 counters on target creature you control
The Blastoise & Suicune deck features Mr
That constant stream of tokens adds both defense and offense, especially when paired with incremental mill effects like Altar of the Brood
The deck almost builds itself from there: ramp early, keep increasing the size of your spells, and let your board scale up along with the amount of mana you are spending each turn
Gallowbraid Gallowbraid is another high-cost, zero-reward commander