[Gameplay][Bug Report]Reksai missed his ult to Renekton while allied Sett ulting

The items on Reksai are The items on Renekton are The items on Sett are All the information are shown in the video, im the Reksai. I ulted Renekton, then Sett ulted him. (Sett is my duo partner and he said he thought he could ult Renekton out and get me out as well) Theres only one source of damage Renekton endured if you see the 0.25× replay at the second part of the video, and it is not my ult. (The description of my ult at that time was dealing 100(+127) physical damage plus 20% of their missing health. The armor of Renekton was only 68. The missing health of Renekton was 1522-502 = 1020 when ulting on the air, considering the armor, which means that my damage should be （227+1020×0.2）×100/168 = 256) And this changed my the process of this game, although we still win the game.(i should be 4-2, but not 3-3 after that)