My Father-in-Law, King Arthur

The modern mage Mo Yu dies during a Holy Grail War fought alongside Mordred, then transmigrates back to the age of Arthur and becomes Merlin's assistant.

Mo Yu only wants to be a quiet mage and, while he's at it, a good son-in-law to Artoria. But things rarely go according to plan...

With Artoria, Morgan, Guinevere, and the others chasing after him, Mo Yu looks terrified and runs for his life even faster.

Those women are all the sort who'd eat you alive and spit out your bones!