Inoki was the man through the 70s-80s, and Ron Tripp and Rickson were through the 80s-90s, although neither had much of an MMA presense but they were universally considered the scariest men on Earth at that point.
Even when Royce won UFC 1, 2, and 4 people still considered Rickson as the greatest Gracie.
Late 90s and early 2000s it was Randy Couture, Mark Coleman, Mark Kerr, and...Enson Inoue (no joke)
By early 2001 there were rumblings of this Russian terminator from the Ural mountains hip tossing trees and putting bears in guillotines.
By the time he destroyed Big Nog the first time, he was already considered "TBMOTP". The rest is history.
Taking a trip down memory lane like this really reminds me how amazing and dominant Fedor was during his prime. 2000-2008 Fedor could maul anyone from any era. Anyone that says any different is just a UFC teet sucking millennial.