i found running apothecary with MM was enough to keep the cycle on track to basically keep the shield up the whole battle this screen shot is for normal
rhazin bog down helped keep alure and armiger in check with turn meter
i found the biggest tip that helped me was getting mm and alure over 200 speed under and was struggling to get turns in time if alure (off affinity) missed a1
rhazin was the main damage dealer and i was able to kill the scarab king before his shield broke ive since 6 starred and fully ascended alure and cranked her speed up to 215, armiger needs 100% crit apothecary as fast as you can build him and MM hitting hard to throw the biggest shield over all he can
good luck i was stuck on him for 3 weeks month 1 and was thinking that was going to happen again - ive now pulled metal shaper aswell so if the vids ive seen with him in are to go by it should be easier now for my team