New rune suggestion for mid mages

In another thread I thought of an example that I believe would make a good addition to the rune system as a choice for mid, or other risky burst mages. After thinking about it a bit I decided to put it in a separate thread and see what kind of response there was as I think it's interesting and feels like it would fit in. Numbers could be tweaked for sure but they do seem pretty well in line with what's currently in play.

Chaos Theory : Gain +12 bonus armor and +12 bonus magic resist. Starting at 6 min and every 2 min thereafter gain a stack of Entropy. Each stack of Entropy applies -4 bonus armor, -4 bonus magic resist and 3 Adaptive Damage. At 7 stacks, entropy becomes Second Law: -28 bonus armor, -28 magic resist, 21 adaptive damage and 10% magic penetration.

Note: the negative effects of _Second Law _ would be applied against the original bonus armor for a net loss of -16 armor/magic resist.

Something like this would let you trade off some early defense for some extra mid-late game squishiness with a little bit of extra damage when capped out at 20 min. This means it brings back some of the old system early game defense but it's still an impactful choice because you are going to be easier to kill in late game but by then you should have some of your core items and would be relying on outplaying rather than defensive stats to survive. I can see this being attractive to some champs/players and some thinking it's not worth the risk for a safer choice.

Is this something that mage players would be interested in? If it were implemented would you consider it an active choice if it were put up against say Transcendence or maybe in the Resolve tree meaning to pick it up you would have to sacrifice going into Inspiration or Domination?

For me I think I would feel it would be a go-to on my support mages but I would only take it as a mid mage vs. someone with high early kill threat like Talon, Fizz or level 2/3 gank junglers. Maybe also where I expect to get poked out of lane for just a bit of staying power until first item buy.