The protagonist travels through time + all-round auxiliary system + the system only provides auxiliary skills (healing, gain, shield, control, etc.) From various anime/games (such as World of Warcraft) + has no attack ability + strong self-protection...
"World of Warcraft": Power Word Shield, Restoration, Lay on Hands, Bloodlust, War Recovery
"RE:0": Parker's shield, Betty's magic protection
"Fate": Avalon (passive self-healing), Master's Command Spell (strengthening)
"Overlord": various strengthening magic
By unlocking the "Flash" of the wizard in "World of Warcraft" (but can only escape, not attack), the "invincibility" of the Paladin, the "Bark Technique" of the Druid, etc.
