Okay so I reopened this thread to say that I think Yhwach should have been upgraded to Multi-Planet with all of the evidence in the OP. I mean, destroying 3 worlds (that should be planet sized) and then combining them is a 5-A feat (unless I am mistaken. If I am, please tell me). Planet level seems too low considering the evidence.
But what about Ichigo's and Aizen's stats? Well, considering Yhwach is far superior to the both of them, I was thinking maybe Planet level Ichigo and Aizen would be most acceptable and reasonable.
So something like this:
Yhwach
Attack Potency: Likely or Possibly
Multi-Planet level (Was going to erase all three worlds and create a new world out of them, backed up repeatedly via statements)
Durability: Planet level via power-scaling to Aizen
Key: With Soul King Completely Absorbed
Aize
Attack Potency: Planet level via power-scaling (Superior to Ichigo)
Durability: Planet level (
Tanked Yhwach's Shadows/Darkness)
Key: Thousand Year Blood War Arc / End of Series
Ichigo
Attack Potency: Planet level (Should be far superior to his Shinigami only powered Bankai form that bifurcated Yhwach twice)
Durability: Planet level (Took multiple hits from Yhwach)
Key: Full Power
Reasoning
Considering Ichigo's in his True Bankai only has his Shinigami powers, it is logical that Ichigo with all of his powers (Hollow, Shinigami, Quincy) should be far superior to it. And the rest should be self-explanatory. Oh and their speed will be the same.
Others
Oh boy. Please go easy on me.
That's some bold claims you got there....