Tryndamere's Ultimate (and other ultimates with a set duration) should have a timer circle that shows everyone its duration.
Tryndamere along with champions that don't have a clear indicator of their key skill durations should have a circle timer that shows its duration.
Egs: Trynd ulti, Alistar ulti, Jax ulti, Kayle Ulti, Nasus ulti, Olaf ulti, Renekton ulti, Trundle Ulti.
They are all key abilities that show when they are empowered/tougher and right now already have a duration timer under their champion details when you click on them.
But frankly, its fking annoying to have to click on them and then keep your eye on that minuscule little clock line in a minuscule little square under their champion details on the top left while they're going all in on you or your team.
Its clarity that Riot has provided before (like Kat and Morg Ultimate showing a circle, and Nasus and Veigar stacks now showing beneath their champ details) And should be again be shown on champs like eg: Trynd, Kayle, Alistar, and Jax.
Because its technically its already there, its just annoying and obscured as hell to try to figure out how long it lasts while you're getting beat into the ground by them