A "negative" ratio-
May seem straight forward to some, may not for others. Its not a concept that exists in the game so I wish to make sure everyone is on the same page. Every ratio in the game takes specified types of numbers and does some math to pump out another number that makes that portion of thier kit stronger, always a plus for every champion with each one that champion has. Never will you buy a stat on a champion and that stat make any aspect of that champion worse, but this is what i propose when i say a "negative" ratio.
Reason why this could be good-
Well each champion is made with purpose in mind, combos and jobs to do, parts to play in general. However not just anything can be put together, do well, and be good for the game. Riot may want to make a strong late game champion but the kit they produce makes them far too weak to succeed early on alone. It isn't as simple as just adding stuff like mobility and crowd control to the kit as these things will make the champions late game state stronger, thus they need to take power out of the kit in other ways. Transversely early game champions need ways to be useful after lane phase so some things maybe lost on their lane phase potential to make them useful later on. These necessities that make sure each champion is almost always playable are also a restriction on what can be happily added to the game in my opinion. Negative ratios would alter this effect.
How would negative ratios do this-
I believe it best to give a hypothetical example to explain:
Imagine a mid lane AP carry champion one would build a team comp around. This champion will do very high damage with very high AP scaling's throughout a focused kit. Only issue is if they solo lane they would lack all manner of crowd control, mobility, sustain, and utility to survive and do well into the mid game team fights reliably. Instead of trimming some scaling damage here for a slow and there for a root, one could put a negative ratio on the slow and root hardly touching the other values at all.
EX. A Q made for the sake of doing alot of damage...
1. A nothing special high scaling AP damage focused Q: 70/90/110/130/150 + (85/90/95/100/105% AP) magic damage
2. What might be done to the Q if a 40% slow for 2 seconds was added for the sake of poor matchups: 65/80/95/110/125 + (75/80/85/90/95% AP) magic damage
_Do this a bunch more across a champions kit, give and take, it may make them better in some ways but its surely will make them worse in the way they are focused. _
3. How a negative ratio/descending values could preserve the original damage values better for later but still allow the champion to get the lane phase defense they need in the form of a 40% slow for 2 seconds without it being broken: 65/80/95/110/125 + (85/90/95/102.5/110% AP) magic damage.
40% + (-10% per 100 AP up to 400 AP) slow strength. 2 + (-.5 per 100 AP up to 400 AP) seconds slows duration.
The final results for each variation of the ability at max rank with no AP vs 400 AP:
1. no AP - 150 magic damage
400 AP - 570 magic damage
2. no AP - 125 magic damage and a 40% slow for 2 seconds
400 AP - 505 magic damage and a 40% slow for 2 seconds
3. no AP - 125 magic damage and a 40% slow for 2 seconds
400 AP - 565 magic damage with no crowd control effects.
Compare them and its plain to see how this concept could allow a champion to get what it may need early on, but as they progress into their ap carry stat they lose the unessecary slow in favor of more damage. This is just one way to utilize negative ratios, they can be just as versitiles as scaling ratios. For an extreme example a champion could be made with both high scaling HP/Resistance values in their kit and high scaling AD/AP values as well without being broken so long as the ratios for damage got negated the more tank stats one builds and the ratios for tank stats are negated the more damage stats one builds. A hypothetical ADC's W could be a long range poke of 3,000 units scaling with AD, however the more AD you buy the lower that range gets so it may have more pay off with less safety however this is better then the ability not scaling much damage at all or having little range with the low damage... either way much less effective throught the game. Lastly I think it would be cool if there was a champion filled to the brim with such examples as i have given changing their behavior slowley over the game with each knew item. Early they maybe a sustian heavy, fast, cc champion only to lose most of that later on wanting to get more out of items rather then their base stats.
Well just a thought at least, maybe there is somthing inherently wrong no matter the hypotheticals I cant see and somone could kindly provide a clear and compelling argument as to why. That or you like it and can go ahead and pad my ego, thankyou ;).