An idea popped up while reading another thread so I created some examples of what you could add into the game. They will definitely need careful review and tweaking, but I think they could bring in more uniqueness in builds.
Instead of copy and pasting, here’s the post I made.
https://forum-en.gw2archive.eu/forum/game/gw2/If-a-new-Sigil-type-came-out/first#post2810825