It is not known to evolve into or from any other Pokémon, despite its close resemblance to Haxorus. However, despite not necessarily evolving from Haxorus, it is known to be a "genetically and cybernetically augmented" Haxorus
No method exists to legitimately obtain WarHaxorus in-game.
WarHaxorus appears once in-game as a Pokémon used by Elite Four member Wilson and is one of the so-called "Six Kings" of his team used in the Hall of Masters. Not much is known about WarHaxorus aside from the fact that it was synthetically created, as described by Sir_Willis_CMS in the data given from the "Hall of Masters Laboratory Records":
WarHaxorus, the dragonkiller. Genetically and cybernetically augmented Haxorus, designed specifically to take out other dragons. WarHaxorus was created from an Axew that Wilson hatched while in the Aroma region.
Because WarHaxorus cannot be obtained by the player, it is not possible to obtain a full list of the moves it is capable of learning. However, there are a few moves that are known from the player's Sigil Hall battle with Wilson: