Can we skip the specifics until we know exactly what magic is, it's role in society & the battlefield, and from whence it is derived?
Idea 1, Magic is Science
People say some magic words, wave their arms around and maybe draw a few geometric patterns on the ground, whatever. The point is that magic is derived from some sort of arcane knowledge and so is practically limitless but comes with an intrinsic catch of some kind, in Wicca this would be "every thing you do will come back to you x3" rule or more scientific version would be "every action has an equal & opposite reaction". So for example if you were trying to heal someone the "life energy" would need to come from somewhere, more often than not from the healer, thus it would wound you. Or if you wanted to cast a fireball you'd need to sacrifice something of the fire element, so in practice you'd throw a handful of brimstone or even gunpowder into the air and shout the magic word for fire; thereby creating a fireball, in theory.
Idea 2, Magic is Energy
Superman looks at something, that something suddenly bursts into flames, now many would challenge the authenticity of such an ability, but just don't argue with superman. Like something out of a videogame people's magic is just some sort of innate power they can call upon without any warning whatsoever, it never stops working (unless the magic user is poisoned or something), and like bodily muscles it seems to grow in strength with use and/or age. The only limitation will usually be some sort of arbitrary mana system whereby the use of one's powers is regulated by their ability to regenerate this mana, unless of course they can buy mana potions, then all bets are off.
Honestly, we can do better than this.
Idea 3, Magic is Thought
Telepathy, empathy, mind-reading, illusions, torture (direct application of pain to the mind), paralysis, blinding, mind control, possession, remote viewing (though it’s borderline metaphysics), memory alteration, disposition alteration, etc. In a world where one’s mind can reach beyond one’s skull, intellectual strength could be likened to physical strength and used upon others in a similar fashion. To watch two minds in direct conflict would be like watching a wrestling match; the various possible holds representing one’s mind achieving dominance over the other in some way. Of course one fighter would need to be considerably stronger than the other if he/she wished to gain complete control over their movements, to physically control them. It would be much easier just to restrain one’s opponent in some way; to bind their hands or cover their eyes, even choking them to death would be easier than complete control.
Metaphors aside an actual conflict between minds would be much more subtle; deception, delusion, willpower and guile would take the place of limbs in a battle that would almost defy comprehension. Fascinatingly all of this would take place beyond the visible world, but it’s effects would be highly noticeable; fighting a physical conflict is hard enough without someone attacking your mind, at best it would be a distraction, at worst you’d be utterly screwed. So naturally on a battlefield where psychics are to be expected you would assign allied psychics to provide cover from the dangers of the ether (the dimension through which minds can connect to each other) and hopefully undermine the enemy. Although psychics would seem to be providing a support role they’re in fact protecting the flanks of their allies; fighting the front line in a battle of psychology.
If one were to lose in such a battle they wouldn’t die, they’d go insane.
That’s about as close to death one could go without actually dying, so yeah it’s bad.