Ultimate Cooldowns are 0s

Okay So I was doing a bit of math from a few patches ago. Riot had made that change to where if she killed an enemy with her ult then her ult cd would be refunded by 50%. It scaled to 50% at lvl 16. I think it was like 15/30/50% or something. but basically, building max cdr (45%) and being level 16 already had your ult on a 29.something cool down. So if you got a kill, your ult would be on a 15 second cooldown. that's crazy right?

Riot didn't think that that was crazy enough apparently. Riot removed the refund cd on her ult but they overall lowered the cd of her ult. And so like, I play lux mid, run cdr in my runes to where I get 20% and then I just buy a . That gets me up to 40% right there, but I also run ultimate hunter which reduces her ult by another 25%. So now my ult is on a 65% cooldown. And the worst part about all of this...if you somehow manage to have 4 cloud drakes, you now have another 40% cdr on your ult alone. Giving you 105% cdr on your ult. Thats the math percentage wise. However, it doesn't actually work this way.

I just got out of the practice tool. and with runes I decided to give myself the extra 5% and the scaling 1-10%. So runes alone I had 15% cdr. Then I bought and which brought me up to 45%. I spawned in 4 cloud dragons as well as leveled myself up to 18 so I could have full upgraded ult, and I also brought ultimate hunter, but you can't full stack it in practice tool because for whatever reason they only let you add one bot to the game so at most you can get is 9% in practice tool with it. It starts you off with 5% though and I decided not to add a bot.

So 5% ult cdr from ultimate hunter, 45% from runes and items, and 40% ult cdr from cloud dragons brought level 16 lux ult down to just 12.1 seconds. I did the math and if you had a fully stacked ultimate hunter, the cd would be either 0s or 9.68s. I think it's the latter though because though all those percentages go over 100%, I think it works more like, you buy some cdr and the cool down goes down. But if it is "ultimate cool down reduciton" then its takes away the percentage off of what the cool down is now. Not off of the BASE cool down of the ult. And taking away another 20% cd from 12.1 is 9.68. If it worked the other way, that being based off of the base cd of the ability, every single champion in the game could have 0s cool downs on their ults...

I also got out of a ranked game as lux mid, I'm in placements right now but I'm s4, and at level 15 with 38% cdr, 4/5 ultimate hunter stacks, and 3 cloud dragons, my ultimate was on a 19 second cool down. What is actually crazy about that, is that the previous game I played as lux mid I had 5/5 ult hunter stacks, 40% cdr and was level 18 with no cloud dragon buffs. My ult was also on a 19 second cd.