Wasn't sure whether to make Behemoth green, red or black. Red because its powers are quite electrical (and very burny). Black because more than any other Endbringer it's all about killing capes. Went for green in the end because green gets deathtouch + trample, which for once I think is justified here, and because Behemoth is "land" where Leviathan is "sea" and The Simurgh is "sky".

It would be.. nice to make the endbringers one in each colour.

And you missed out the teleporting city-making tower one.

I would also just flat out go with Annihilator. They're the same role as the Eldrazi; why not make use of the tech?

Because that makes them too much like Eldrazi, taking away from their distinctiveness a bit. Annihilator is more about destroying lands, usually, which is especially Leviathan's role. Behemoth does more killing of people.

"Missed out" Khonsu - I also didn't mention Tohu and Bohu, because I wasn't talking about them yet. But the fact there are five (counting the two of them as one Endbringer) does strongly suggest putting one in each colour.