[GAMEPLAY] Tri-Force Has An Unintended Interaction with Corki's Passive

As of patch 7.12, when Corki builds Trinity Force, The damage from the Spellblade passive applies incorrectly. As says: "[Spellblade] deals 200% physical damage of base attack damage on hit." However, Corki's passive turns 80% of the damage from his basic attacks is converted to magic damage. The passive shouldn't affect on hit effects like , but Trinity Force's passive appears to be applying 80% of its damage as magic damage. I have tested the same interaction with , but Sheen does appear to apply only physical damage. This bug is critical to game health because nearly every build includes a , and since relies off of magic pen through items like , it is usually dealing more damage than intended. It also makes Itemizing against harder because it reduces the effectiveness of armor. Considering that Corki's burst is usually somewhat evenly split between physical and magic damage, this makes his damage much more magic focused, which can disadvantage people who built armor against him.