@tblst the problem with guts power is that, it is not a skill, is not a technique, is not really a special power, is just guts technically everyone should have them in battle manga, big guts makes the gutsy character look great, but it also makes every other character look like trash, because they just don't have the guts.
Gust power only works when it comes to play and once the battle is over, you get to say: "oh but if X or Y character had fought, they would have won too, they are also gutsy."
With Tetsuma however you don't get to say that, he requires a special kind of guts, a kind of guts that no one else has, and that makes everyone else look like trash, name em they trash now, gutless all of them.