[GAMEPLAY] Garen True damage ult vs. Master Yi mediate

when i faught against master yi as Garen, and he was low enough health to be executed by my ult, i applied the Ult just as he began meditating, and it did very little dmg to him, something certainly not worthy of an ultimate at lvl 2.

i can understand that true damage should be shielded by abilities with some champions such as vayne, but as its an ultimate and not a basic attack, i feel his ultimate should be True damage regardless of any champions shield.

i dont know if this is a bug, but im sure someone will reply and let me know.