I'm thinking of two options, and both do not really require any retconning.
The first one is as I mentioned a couple of posts back: he uses concealer to mask it up. Over the years, he's become pretty damn good at it.
The second option is pretty much like Bob said, except that it appears when Zeke is starting to channel Raven-sama (Zeke is still very much Zeke while
Raven-sama just smiles and lends his avatar all the power he needs - like Naruto and Kyubi, only this time the Kyubi can intervene when it so chooses). Think
of it like a Diamondback's rattle; you get a warning cue that things are about to get really, very bad for you and you may want to back off.
The first one is as I mentioned a couple of posts back: he uses concealer to mask it up. Over the years, he's become pretty damn good at it.
The second option is pretty much like Bob said, except that it appears when Zeke is starting to channel Raven-sama (Zeke is still very much Zeke while
Raven-sama just smiles and lends his avatar all the power he needs - like Naruto and Kyubi, only this time the Kyubi can intervene when it so chooses). Think
of it like a Diamondback's rattle; you get a warning cue that things are about to get really, very bad for you and you may want to back off.