[Ca12nag3]

Spoiler for ch75:

Im not sure if thats due to plot or art, Imai could have just implemented the idea of the bandage later, remember that the symbol on Arclight only shows when he activates it, so if this is a similar thing it would fade once he stops using it.

For plot, even if the bandage is put there to hide it he could have put it there himself he dont need some old geezer to be his nanny, and the power he could have had for a long time now... So he could have hidden it from Blade if he used it before due to the bandage.