Naoto's quirk allows him to heal/stabilize minor and serious injuries. When he activates his quirk, Green flames appear either around his fingertips or his full hand, depending how much power he needs. Minor injuries don't take much power and energy to heal or stabilize, but when it comes to more serious ones, more power and energy is needed.
To heal/stabilize, he applies pressure on the area and then the flames are going to start the healing process. At first, the sensation is like when you apply alchool on a wound, for the first few seconds/minutes and then a soothing sensation is felt.
He cannot use his quirk on himself. However, he naturally heals a little bit faster than others, when injured.
The drawbacks: his quirk drains his own energy when used. Depending how much energy he spends while using It, his eyes will change; the colors and light in them will slowly fade and his heart beat will slow down a little too.
When his eyes reach the last example, It means he used way too much energy with his quirk and he is about to collapse. When that happens, he needs to rest for a least ten to twelve hours.
Also, even if his flames don't hurt/burn, naoto learned to use them during fights. He can blind the enemy with the strong light of his flames, which can give him or his allies the opportunity to hit, parry or dodge the enemy. Plus, a strong light in the eyes can make someone blind temporarily depending the situation and how strong is the light in question. It can be useful if used wisely.
