he's physically strong like super extra strong compared to the people in re:zero even if he can't control it show how strong he is because in the fight scene if you have the body of artoria you don't need magic burst or mana burst or whatever you wanna call it to defeat that vampire. and for the goal I mean why not just let him know that going back to his verse is impossible and then let him fight againsts someone strong like the witches of sins and he failed to save someone
I suppose if you really wanna get crazy with it since he has excalibur Morgan you can give him dark magic as well and go full dark souls with it like how through the use of Gwyns magic he made illusions and Time shenanigans( the ringed city) ,but hey what do I know you do you just so long as you continue this story. The original Re zero why me was so slow with its update frequency so I'll be happy as long as it doesn't get that bad
A suggestion author san. Plz Nerf the mc a little.He has higher parameters and skill ranks than the actual servants. He has no reason to possess Excalibur Morgan.There is no EX++ rank. I suggest that MC should be influenced by Arthur's Instinct and desires due to possessing his body.Mc should experience a dream cycle of Arthur's life.This will cause him to develop his skill as well as help in becoming a stronger individual mentally.