Originally posted by The Ion
Stop right there. I just went to Classic Marvel and found listings for such mainstream DC characters as Alchemist, Blok, and Catspaw. 😕The Fury last appeared in a late 2004 Uncanny X-Men arc and at Marvel it doesn't get more mainstream than Uncanny X-Men. However I would say mainstream is a character that anyone, not just comic fans, could tell you about and theres only a handful of them.
If classicmarvel doesn't list an extremely powerful and unique character then it is probably not as well-known as Doomsday. The fact that evryone said who's The Fury and that the thread is not evengers vs fury kind of gives you a clue. Plus Fury could be and was decommissioned and appeared in an alternate universe and so (coming back to the main point, that dc was stupid to make an unkillable and adapting character AND make him important and basically irremoveable, which you haven't really challenged) marvel writers have not created a Doomsday like character who has to come back, dc writers are stuck with him unless they decide on another huge retcon.