Karthus bug/Baron bug
When i got a kill while in karthus passive and the person had a buff, i would get the buff when i respawned and it would last the normal amount of time but leave the visual of the buffs throughout the game. Also with the new baron, if you use a gap closer such as master yi q, jarvan e+q, wukong e, etc. onto it, it would make it so you can not move or use abilities for about a second.