Gilgamesh can be portrayed as a powerful and haughty figure. He could walk around the world of Danmachi with an air of superiority, looking down on the 'lesser' adventurers. His flamboyant style and his love for grandeur can be emphasized, like always wearing the most elaborate and expensive armor.
In the story, Gilgamesh's age isn't precisely defined. He's presented more as a mythical and timeless hero rather than having a specific age attached to him.
The story of Gilgamesh is extremely old. It was written around 2100 BC and has endured through the ages. This makes it a significant piece of early human storytelling and cultural heritage.
In the end of the story, Gilgamesh returns to his city, Uruk, having gained wisdom and a new understanding of life. He accepts that death is a part of the human experience and that his deeds and memories will live on even after his physical death.
Gilgamesh was changed quite a lot. He went from being a self-centered and prideful ruler to a more reflective and empathetic individual. The experiences he had on his journey led to this transformation and a new perspective on life and his role in the world.