I tried thinking of a good description but I couldn't, in short: radahn was abandoned in the forest when he was young, he named himself radahn, he's the only male that can use magic, magic is stored in the boobs, except asuna, asuna is a gender-bent Asta and I'm giving her big boobs cause I'm the author, anyways radahn uses gravity magic, but his magic control is worst then Noelle and can't be improved with any amount of training, so he forged two massive swords to help channel his magic, along with armor do give him the closest thing to anti magic armor, all magic attack still hit, however theyre so weakend i dosent matter and the are constantly weaking while radahn has his armor also, unfortunately, radahn will not have Leonhard and his size will be reduced (asra type build, taller then just a foot shorter then yami but moderately buff, not gross buff but not athlete buff) anyways, in return... radahn will be physically capable of having sex with his harem without *hopefully* tearing them in half
(P.s The reason he's not a raping animalistic caveman is cause I'm the author and I say so, but if you need a reason, he bumped into a village (hage) when he was young and they taught him about everything, manners how to cook, forging, etc etc, also he became friends with Asuna and Yuma as Asuna fell in love with him immediately and they started working out together, radahn surpassing Asuna because of his unnatural physique, and Yuma crushed on him because of radahns supportiveness and willingness to let Yuma (try) to teach him magic control and that's also how he learned about the mkee (magic knights entrance exam)) also polygamy is the norm in this book (if you can prove your stronger then your women, either in fights or in 'fights') also in this story you have to be 18 to get a grimoire or become a magic knight if you don't understand any of this tell me and I'll try to explain
Also, none of the characters belong to me Yada Yada Yada