Illaoi E Damage Cap

Not sure if this is a bug or intended, but at the very least some information is not being displayed on the amount of damage Illaoi's E can do to a champion at very large amounts of AD. Last night I thought I would do some science and see what would happen if I went into a bot game and got enough AD to make Test of Spirit echo at least 100% of the damage the spirit takes back to the original champion. I ended up with right around 1000 AD and in the tooltip, Test of Spirit SAID it was echoing about 125% of the damage the spirit took. Despite this, after E'ing a bot and killing the spirit without damaging the bot, they would always have a couple hundred health left no matter what health level they were at when I took the spirit. There were not enough heals or shieds to stop them from taking enough damage from the supposed 125% echo to not die, but yet they did not. I guess this isn't super relevant to actual gameplay as this would never happen in an actual game, but at the same time it feels moderately wonky to have a tooltip tell you an ability is going to do this thing and this amount of damage and then have that just not happen. Whether it's a bug or intended, I think clarifying a damage cap on Test of Spirit would be nice, just for transparency purposes.