Towns have a combined color identity of every colored mana symbol that appears in their rules text
Also, if you read the lore youd know that these Nephilim arent the real Nephilim, theyre just magically crafted Nephilimmy things, and theyre sort of pre-god gods of Ravnica, creatures that are so transcendentally powerful and important, that they dont even need worshippers or sacrifices their cult calls upon them to be seen not because of their actions, but because of their existence being so fundamentally powerful and dangerous that their presence humbles people
If a creature is dealt damage equal to or greater than its toughness over the course of a single turn (whether it be combat damage, damage from spells or abilities, or a combination of both), that creature is destroyed, and it goes to its owners graveyard (or "dies")
Take out Seal, since the 500 boost for your vanillas isn't worth losing your entire ED (especially since the ED has so many good cards available)
You can only activate 1 "Apex Predation" per turn
But if you have some quality links to sites dealing with such topics, let me know and I will add them here