20k feathers+Corrin question

so my current merge project and potentially my first +10 unit is going to be Azama(friend code: 2883147505) and i've been dedicating all my feathers to him lately but there hasn't been any banners where i summoned on colorless orbs and i'm fresh out of merge fodder.

should i save up on feathers and wait for more or should i start promoting some other units i want to use? (right now i'm holding off on Kaze, MCorrin, and Lilina)

Corrin also has swift sparrow because i thought it would synergize well with Yato's darting blow 2 but now Fury has better synergy with the refine. Should i just go on and use swift sparrow or should i wait for another good IV Corrin and fodder off this one to someone else?