Mikazuki Munechika is the first collab unit released as an SSR in Granblue Fantasy and it shows length about how weak collab units were back then.
His kit is:
1) First skill is a plain 500K nuke on 5 turns cooldwon
2) Second skill is a 1000 party wide heal + clarity on a 8 turns cooldown (horribly long)
3) 25% party wide damage cut on a 4 turn cooldown
4) Ougi gives himself 2 turns of guaranteed DA
5) Passive that increases CA Dmg (but not cap) based on how low his health is.
As you can see, generic kit trying to cover up all bases, but failing on every one of them. A glorified SR unit marked as SSR for marketing purposes.