Izuku's quirk is Energy Converter. It's an Emitter/Stockpile type that allows him to pull energy from an internal stockpile and convert it into other forms of energy. Plasma, Lightning, Thermal, Kenetic, you name it. As long as it is Energy, he can convert the stockpile into it. After conversion he can telekenetically control the result.
The only issue is that he doesn't have a stockpile. Due to an unfortunate error in his genetics, Izuku got the ability to manipulate an inner stockpile of energy but did not get a way to collect said energy. The specifics aren't clear since he cant show it off, but basically, the quirk can only build up his stockpile if he has energy in it, and since he has no energy in the first place he has no way to build upon it, and as a result his stockpile stays empty.
Should a second quirk that can stockpile energy be added, the two will seamlessly fuse together, and unless he drains that quirk dry, he won't have that issue anymore. It's later revealed that Izuku is the desendant of the OFA Stockpile Quirk and that its theft was the cause of his defect. Its theft was sloppy, and as a result, it chopped off Izuku's ability. Years later, that half-stolen Quirk Factor gene was passed on to Izuku via genetics and bad luck.
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MHA Story And Quirk Ideas
FantasyStory/Plot and Quirk Ideas I have no motivation to make, but think sound really cool! The entries with Quirk : [Name Here] means this entry is about a quirk idea! The entries with Story: [Name Here] means it's a story idea! If they're combined, it m...