Thanks for the recommendations. I definitely meant to put
Shizo, Death's Storehouse in. For the rest:
I'm not really interested in aristocrats effects because I want creatures on the board. I need a whopping 10 for Lathril's second ability, and I'm not sure how easy that would be running sac effects.
For the same reason, I'm not sure about the kaldheim elves that rely on creatures dying. I'm thinking I'd rather run more protection than plan for things to die so I can draw.
Skemfar Shadowsage seems a little redundant. It's not super useful unless I have a lot of elves, but if I have a lot of elves, I'd probably be using them for Lathril. If the ability wasn't only on ETB, or if it had more use after coming down, then maybe. As it is, I'm not sure 4 mana is worth it.
I ran
Throne of the God Pharaoh in Ezuri for a while, but I realized that it didn't help me win any faster and I often wanted to leave elves untapped for chump blockers or fast access to mana. If only it weren't on MY end step, it would be a lot more interesting.
Species specialist is just a worse
Skemfar Avenger to me. Yes, it triggers when a token dies, but I still don't want to depend on my own creatures dying.
Plumb the Forbidden seems a little pricey for what it does in this deck. I'm not sure it's worth running through half of my board and a lot of life trying to dig for a combo piece, at least not when other draw options work too.
So, thanks for the response, but I'm not sure a lot of these would fit that well into my strategy. I can definitely see how they would work in a Lathril deck, but I think they run too counter to what I'm trying to do to be terribly helpful. Who knows, though? Maybe after playtesting, I'll come back and try them out.
EDIT: You know what? On second thought, I think I'll playtest
Skemfar Shadowsage as an alternate win con. It would be easy to tutor for, and making enough mana to play it 10+ times would be easy enough if I have
Cloudstone Curio or
Temur Sabertooth.