Azir and rift herald.
I dont know if this is a bug or not but azirs soldiers dont work with the rift buff. 
2 Comments
Do you mean applying damage from the buff? It's applied on-hit and they do not apply on hit effects, so no it wouldn't.
However, I haven't tested this out for myself, but I know that when the phantom hit was still on Sated Devourer it would apply on-hit effects as if Azir was attacking directly instead of his soldiers. Now that the phantom hit is part of Guinsoo's Rageblade, it may work with this as well.
I assume the buff charges is an on hit effect. Azir's soliders do not proc on hit effects, only spell effects (i.e. Ludens/Rylais).