The Wolves of Brandenburg
Gilgamesh is an Ancestor Spirit of the Silver Fangs. His features are very indistinct and hazy, and there always seems to be a bright light behind him obscuring anyone’s sight. It is as if little memory of his features remain.
Whether Gilgamesh is THE Gilgamesh, is unknown, but the Silver Record has legends of a similar figure in the Middle East long ago when the first ideas on kingship appeared. Although considered a founding figure of House Wise Heart, many of the Silver Fang other houses bear lineage to him as well.
Gilgamesh appeared when Erwin had a botched attempt at summoning an Ancestor Spirit to reveal additional information on his own heritage. Rather than summoning a more recent Ancestor, this ancient spirit arrived instead. Erwin has contacted the spirit since then to learn Gifts.