Kiri can renforce his quirk making it stronger after taking damage the more damage Kiri has the strong the quirk recovers. But tetsu has to have high iron intake for his to be stronger there is only so much you can eat. That is the difference in their quirks.
@@AxiEisapretty sure they mean because bakugou typically calls him and everyone else by a nickname, so it's rare for him to use somebody's real name lol
