Original Sin maybe?
It was successful, but did it pioneer anything? Was it something new and creative?
Did Explosion?
You're only thinking of one factor the hall is based off. According to the call of fame, there are four:
1) Dominating success in combat
2) Pioneering or perfecting influential designs
3) Having great fan or entertainment appeal
4) Otherwise making a lasting impact on the sport
So Explosion / Eruption would qualify for 1 and 3, and I suppose 4 to a certain extent. Obviously I don't know as much about Original Sin but 1 and possibly 4?
With regards to point 2, Explosion did "pioneer" Hardox on featherweight non-boxes, and I suppose if I was clutching at straws it perfected that particular design of flipper that's not the typical "pure wedge" shape. But I admit these are a little bit far fetched :P