First of all, I love this skin, the eclipse on his bomb is golden.
With Thresh, Elise and Kalista you guys gave a very good explanation for them. Of how the Blood Moon would represent the way they're seem on a different culture (Ionian) that not the Shadow Isles. But with Zilean...? It really doesn't make any sense.
Also, it's the sixth skin from the Blood Moon line, I think this is a first. I thought you guys wanted to make a whole team with a skin line and then retire it, but then there's this. Katey even said when replying to GotS Rek'sai that "there were only 4 yet."
And on top of it all there's the Fiddlesticks skin which could easily be a Guardian Of The Sands but was strategically changed to "Risen". (Which also raises questions regarding Final Boss Veigar, could there still be an Arcade middle laner? I think so, considering Skarner, Kha'zix and Fiddlesticks are more oftenly seem in the jungle, although one could argue for Skarner Jungle, Kha top and Fiddle support)
I propose this skin to be changed to Eclipse Zilean and that on his ultimate the screen should go darker representing an eclipse, instead of brighter like all the other skins.