We don’t know, but we could make a pretty good assumption based off of what we know about the others.
In Irenics case, he is a one time boss, and usually carries weaker angels on top of it (but sometimes a joy)
Thrones: “Members of the First Sphere. They are inhuman in appearance and serve as mini-bosses. They are very rarely encountered in numbers greater than one at a time.”
Cherubim: “Specializing more in brutal strength and direct combat, members of the Cherubim rank are deadly combatants, so much so that even though they rarely appear alongside other types of Angels, they are still some of the most difficult encounters in either game.”
Seraphim: “The members of the Seraphim rank are some of the most dangerous enemies in the game and the highest-ranking angels of the First Sphere. Gameplay-wise they are frequently attributed by players as being even more difficult than the higher ranking
Auditio.”
By these definitions it’s better to assume Irenic would classify as a Thrones, since only one appears at a time in the level. They are not brute force fighters like Cherubim, and do not have the skill set to be dangerous enemies like Joy, or Glamor. (Irenic only drops bombs as you fight it, so..)
if anything I would scale seraphim higher than him, while the others have a likely.
also just realized you said “hold it” because of your ace attorney profile photo..