For halloween skins Riot could've thought of better skins for players to get :/ 
could've gotten a skin like from what i have thought of graveyard where his q is a pumpkin that comes out his passive stacks make a bat his shield is a coffin and his w makes a ghost underneath them and his ult when he hits the ground it makes graves instead of ice or whatever pop out
Or make his shield a tombstone. Coffin or tombstone both fit.
Anywho, I feel that Necromancer 
is optimal for a new Harrowing skin. Change his soliders to zombies/skeletons (Maybe even both), give him some cool black robes (Or even make Azir himself a zombie) and then make his ult a line of tombstones. It fits pretty well, and actually makes sense since Azir was brought back from the dead according to the lore.
