Brauner is fought in Wygol Village, having led a vampire raid on the village in an attempt to lure out Gabriel. After Gabriel defeats a big number of Brauner's minions, Brauner engages a single combat with him, Gabriel gains the upper hand by ripping off Brauner's wings and then defeats him by cutting off his right hand with his own sword and lodging the blade in his head, then staking him through the heart with the Combat Cross, killing him.
"This Vampire is a powerful demon, turned by the Dark Lord long ago.(...)"
Brauner is presumably named after the main antagonist of Portrait of Ruin, a once-human painter who became a powerful vampire after the loss of his two daughters during World War I and took control of Castlevania, attempting to use its power to take revenge on the human race Dracula had repeatedly failed to destroy.
Unlike his original timeline counterpart he is a Demonic Vampire (a spawn of Hell possessing vampiric powers) who serves a more powerful human-born vampire.