I'm pretty sure the translations for Guzma involving keeping stuff alive is wrong. They're getting that meaning from the word 生かす, which means to keep something or someone alive. Already the way the sentence is worded this would be strange word choice, you don't generally use the word about yourself (自分を生かす), and using it refer to an enemy would make it sound like you're talking about letting them go instead of killing them, which is one way the word is used.
But that's not even the word Guzma is using, here it's spelled as 活かす, which is pronounced the same but has a different meaning of "to make use of" or "take advantage of". It should also be noted that he's using the word 相手, which people translated as enemy, but tha't not quite right. 敵 means "enemy", but 相手 means more "opponent". The word is usually used to refer to the other people you're playing or fighting against in a game or battle. So he's not referring to some person they have animosity towards, but specifically someone they're planning to have a battle with.
So in other words, what he's saying is more like "taking of advantage of your opponent['s skills/what they do] will get you to make full use of yourself [your own skills]."
