TBH Blade didnt save Marvel. In fact it was a sign of how much they fukked up vs. a sign of success.
Lil' backstory: Marvel went bankrupt towards the end of the 90s and to save the company, they sold off their film rights for various characters. X-Men/Fantastic Four to Fox, Spider Man to Sony, and for some reason, Blade to New Line Cinema.
Marvel probably thought they got away with the finesse jobs of all finesse jobs
when NLC bought rights to Blade. Blade had always been a D-Lister as far comic popularity. Hell his only success at that point was based on proximity to either Spider Man or Ghost Rider.
Blade hasn't even had his own solo title in marvel for like 20 years, even with the success of the movies (marvel and NLC had little to no working relationship).
What they didnt realize is that backed by a strong script from David Goyer, Wesley Snipes would turn in a really inspired performance of the character (so much so that Comic Blade became nigh-identical to Movie Blade overtime) and the film would go on to be hugely successful.
Marvel was prolly looking at the first blade box office numbers like