A few ideas for future champions,

Draven with 1 lifesteal item heals for over 100 per hit, so I think that's pretty sustaining adc already... And Fizz is kind of yordle, assassin >.> And we do have Vlad.

loving the darkin mage idea would work amazing as varus's sister

Kitty Katarina is actually right about Fizz being an assassin Yordle. Read his lore in the client, they updated his lore and he is an aquatic Yordle now. It's just that Riot didn't update all other lore sources yet, but he is officially a Yordle now.

Kitty is wrong about Vladimir and Twitch, though. Twitch is in no way related to Yordles, he is a chemical waste induced mutated rat. Vladimir, like you said, is a hemomancer using blood magic given by Darkin, not a vampire.

A young anime girl vampire with a scythe is actually something that one designer at Riot wanted to create for a long time now (don't know who anymore).

We could definitely use another female Yordle, there are just 3 compared to the masses of male Yordles.

My only complain.... your suggestions are based alot on Runeterras magical world, we got alot of magic last year already. I hope we see other types of champs next. More from Zaun and Piltover, maybe a bandit from Bilgewater and so on.

My personal biggest desires are: A maid from Piltover Vault tank from Piltover Herbal alchemist from Zaun Hacker from Piltover Medic from Piltover (yeah, all my ideas are about Zaun and Piltover :P)