Reinforcement Magic: Deku uses this form of magic to enhance his physical abilities.
One For All: Full Cowl (ワン・フォー・オール フルカウル Wan Fō Ōru Furu Kauru): With an open grimoire, the user gains access to stockpiled power, granting him superhuman strength and greatly enhanced agility and mobility by spreading his power through his body. When in use, the user's body glows with a green electric aura. If the user does not keep One For All below his current limit of 20%, his body can be immensely damaged by the force of his movements.