One of my headcanon regarding Gladio's tattoo is that it was a gift to Ignis and a milestone of their relationship. I developed this idea after I read official works & Ultimania and was glad that nothing mentioned the origin of the tattoo.
It was after I finished all settings, I realized that the meaning of the tattoo (plus it's a family tradition) was mentioned by staff in an interview and then in the blog of Famitsu.
But I don't want to change it. So here it goes: I know the tattoo has to be " Enkidu", but the person could choose its pattern and size. So Clarus's tattoo is different from Gladio's.
Ignis is blessed with good eyesight and strong analytical ability, in a sense, hawk eye/ eagle eye could be his middle name. So he choose the pattern which put the head of the eagle close to his heart, as a gesture of love to Ignis.
Therefore it would be very interesting to observe the new scars on his chest which Gladio returned after CH8, O wonder where it ends? If it ends up cutting through the eagle's eye? Did the staff gave a faint hint of what is going to happen in the future?
Gladio with new scars could only be seen on MOD like this. https://nexusmods.com/finalfantasy15/mods/108
I really appreciate the maker who chose to blind the eagle for it fits my headcanon so perfectly.
Finally, I know nobody cares, but when I write about this story, the tattoo artist who made such beautiful work on Gladio is this guy from other game (Dmmd). Check out his work on the other character, it's amazing XD
Somehow I feel relieved after saying this. Now I have to move on.