Iterating U/B: Learning from Death?

So I'm still thinking through how to capture the top-down concept of the cephalids in Guthraham, who are all dying of spreading plagues and are desperately using their deftness at magic and science to try to figure out solutions.

I was thinking a bit more about the recursion concepts with spells and the graveyard and how to make it connect with reave without giving blue access to reave. And I just kind of realized that maybe "death triggers can help you win" can be a good way to connect to connect blue and black thematically in this set without having to work out another mechanic.

So some tweaks to my last iteration of U/B cards, which I realized were too strong to return from the graveyard with no cost. Especially if I want them to be at common:

So now they have death triggers and a cost to bring back from the graveyard. And they feed reave, especially any higher rarity cards that count how many cards have left the graveyard in a turn. And it still works very well with the U/B signpost uncommon cephalid.

I do have to worry now about creature recursion spells and infinite loops. I think I do need to put a recursion cost on the Shambling Follower. And no free sacrifice sinks.