Quote Originally Posted by KorvinStarmast View Post
If you use pantheons from Greek or Roman mythology, Ares or Mars fills the bill.
Can be reskinned into almost any setting.
Heck, the Greek pantheon is part of Planescape, so you may not even need to reskin. Ares is a better fit here, for what it's worth; there are a bunch of differences between the Greek Ares and the Roman Mars. Mars is a protector deity, father of the people, and a bringer of war to secure peace and prosperity (Romans were big on not doing wars of conquest, which basically meant finding increasingly convoluted ways to cast their wars of conquest as defensive conflicts. Some thing never change!). In the Roman tradition, Mars is almost more akin to the aspects of Athena concerned with warfare and strategy. Ares is ravening, brutal, concerned with the physical elements of warfare. He's probably more like what the OP is looking for, though he might be a little too evil if OP wants something more like battle as a morally-neutral Platonic concept than battle as murder for glory and feeling the blood splash on your helmet as you tear the spear from your foe and grind him into the dust.

Other Greek options, if that pantheon is on the table, are Pallas and his daughter Bia, or Agon. Pallas was a Titan who is associated with warcraft. Bia is the personification of force or might, and is basically a blank slate; you can do whatever you want with her. Her only mythological depiction is in the binding of Prometheus. Agon was maybe more of a concept than a deity, but is the spirit of striving in conflict and seeking victory -- there was a statue to Agon at Olympia for the Olympic Games, and it's where the words protagonist and antagonist come from. Agon isn't associated with war, but I don't think you'd be going too far to ask for its worship to include the war domain.