[GAMEPLAY] Nocturne Ult + Blade of Drakkthar bug

Watching an ally duel a with and she spend about 10 seconds fighting without going out of vision, i finally get in range and ult her. Fly to her and i die (in a fight where i never lost vision of her). turns out her blade of draktharr did the true dmg proc to me despite 100% always in vision.

Didn't ignite. Didn't have conquerors or enough pen to do true dmg to me. Just a blank icon then "Here's a bunch of true dmg"