Planeswalkers Ashiok, Nightmare Weaver: Having played with this card myself once or twice, I can say that its not as good it seems
And aside from being stuffed into decks ramping toward Eldrazi, Blightsteel Colossus enjoys hanging out with Braids, Conjurer Adept, pia coladas with Muzzio, Visionary Architect, and long walks on the beach with Ilharg, the Raze-Boar
The biggest, baddest creature in the red lexicon must be Akroma, Angle of Fury
Summon: Primal Odin This six-drop 5/3 is next
Rain of Filth isnt for cowards as it requires you to go all-in to extract the most value from it, but it offers a significant mana advantage to get you there
Sure, there are some other Merfolk, but drafting a bunch of Volshe Tideturners and Voda Sea Scavengers is already enough weaker than casting Captains Call as a baseline that its pretty easy to understand why this isnt a great idea