@Davlamin You have now made it perfectly clear what your character is capable of, which is good. All criticism from here on is just for refinement or suggestions. Based on what I've seen of the characters in this arena so far, your character's magic puts him at the higher end of power mainly because of the strength, speed, and defensive buffs which can be stacked on top of one another. This is not a bad thing, but you may have a little difficulty finding an opponent who can deal with all of those resources. Ten minutes is an arbitrary limitation because the battles in the arena generally only take place over the course of a couple of minutes, so they may as well be indefinite. Lastly, and this is just a flavor-based suggestion, the spells seem to be all over the place thematically. Many characters either have a motif of similar abilities, or justify diverse abilities with some kind of common source. "He studies magic" is kind of vague for justifying physical buffs, elemental attacks, and magical wards. My suggestion would be tying each spell into your character's backstory, briefly justifying why he would know it. As your character is, though, it looks ready for combat.
