^ This. This. OH MY GOD THIS.
In general, there are four recognized power levels in turn-based combat: Realistic, Unrealistic, Mild Powers and Powered. (These terms may vary depending on who you're talking to.)
Realistic is as the name implies: No magic of any kind is permitted on the battlefield. This is the tier in which OOC knowledge of specific combat arts is most likely to come into play when determining the victor, as large amounts of effort go into describing minute details of footwork, stance, distance, angles, and other factors such as the nature of any wounds sustained.
Unrealistic is what I like to call "Street Fighter tier." Many of the characters found in fighting games usually take their chosen martial art to "the next level" with superhuman feats of athleticism and the occasional ranged attack being launched from their bare hands, which is basically this tier in a nutshell. As with the video games, the emphasis is on distance, position and timing in order to land the decisive blows.
Mild Powers is what most people think of. Relatively low-level magic capability, elemental manipulation, enchanted weapons, etc. This is the most accessible tier, but it is difficult to have reliable success in this tier for exactly that reason, as chances are you're going to go up against a character that happens to be singularly suited to taking down your character type at some point. The emphasis starts to shift from round-by-round tactics to overall strategy, as it's more difficult to get people to fall for your brilliant finishing combination right away while still allowing for the match to be decided in close quarters.
Powered Combat is what most kids that don't have too much experience with the activity think of. They want to power up to Super Saiyan 5 and blow their enemies away with the godlike power of the Kamehameha Wave, assume the form of the nine-tailed fox and rip their foes to shreds before they can blink, or at the very least reach through the fabric of space-time to stab the opponent from behind when they're standing face to face. When done properly, combat on this level becomes a game of cat and mouse, as both fighters try to lure their opponent into a lethal trap without falling for their opponent's tricks. Often, the fight goes to the one that lands the first blow, as there is usually sufficient power in that one blow to render the victim unable to continue, or at least unable to defend himself from what comes next.
How long will he keep on fighting? How long will his pain last? Maybe only the X-Buster on his hand knows for sure...