@S121
Beowulf Devil Arm:

A set powerful gauntlets and greaves that are "Blessed with the Sacred Light." The gauntlets when worn increase a person's strength and speed greatly when attacking. They also allow the wearer to attack with light infused techniques.
I imagine that if John were to get the Beowulf it would end up fusing to his suit, the gauntlets basically becoming the new arm guards for John's suit, and the greaves becoming the new boots. With this happening John's suit won't really be effected by it. In fact he would maintain all the same abilities and all he had before. The only thing different is with these magical gauntlets and greaves which would fuse with John's suit, John would actually become much lighter (his strength and speed won't increase, John would basically become much lighter when wearing his suit with the Beowulf fused to them. He would basically weigh the same weight about the same weight as Dante ) Also with Beowulf fused to his suit he would be able to control and focus his light magic even better than before. Able to channel his normal punches and kicks with light infused magic to increase his damage output.
I also imagine him obtaining a sort of Devil Trigger of his own with the Beowulf. With Beowulf John would be able to access a sort of "Light Devil" State. In this state John's suit would become steel grey, with white glowing veins covering his entire armor. He would also obtain a pair glowing white angel wings. He would also emanate a powerful glowing white aura of light magic, and floating white angels which constantly float around his body when in this state. In this state John would be almost weightless, able to fly faster than before, and would have far greater power with light magic. He would also get a self healing factor while in this state. However he would only be able to maintain this state for short periods of time. This state will be granted to John, because of his already current abilities in light magic. The Beowulf would just amplify these powers even more so to the point where he can get his own sort of "Devil Trigger"
I know OP as hell it sounds, but remember I plan on giving everyone at least 1 Devil Arm which could put them on a similar level of power.