Time travel Au where Azik goes back in time. Probably a little bit after the Megose incident, but when Klein takes him to his castle and he regains some memories could also work.
The fun thing is that Azik has only half a soul, which probably makes it much easier to send him back than someone with a whole soul. Plus he'll be landing in a body that Also has half a soul.
And like maths probably a bit funky but if you take 1/2 Azik soul and add another 1/2 Azik soul. Then you should get approximately one whole Azik!
Meaning no more death amnesia cycle! He's a full blown Angel at the peak of power with a hefty dose of humanity.
And the first thing he does is start praying to Klein.
Who is low-key freaking out. That's Mr. Azik! Why is he praying to him! How did he learn Kleins honorific name!
He brings Azik up to the grey fog, stressed about lying to Mr Azik. Only for Azik to just casually greet him as Klein. Complements him on the sepherah castle. Is just himself.
Anyways it's just a comedy of Klein being confused as to Why Exactly his former professor who is a fucking Sequence 2 Angel wants to join his tarot club. He's not complaining, it really helps Mr Fool's reputation to have an Angel under him. But Why???
Meanwhile Azik just really wants to court his cat. Because while the merging of past and future Azik means he's not really at risk of losing control. It Does mean that tends to forget that he and Klein aren't together yet and thus how familiar he should act.