Liandrys torment bug

So as the title suggests i was in a game playing velkoz bot lane as we were messing around and as a teamfight breaks out jumps out ults me and then uses his E i got shielded by the lux and hourglassed just to noticed that the damage was about 4k through ticking of just torment and E now i had no mr and i get someones gonna say that but he barely had 400 ap and still did that much damage with torment i feel that is either bugged or in need of visiting

Note:did have rylais but still 4k burn is insane...okay roughly 3.6k but still thats alot for a under performing mid laner