Changing Hero size when a Hero levels you say? That should be pretty simple:
<<<SET THE VARIABLES FIRST>>>
Events -
>Map initialization
Conditions -
>NONE
Actions -
>Set HeroLength = 10
>Set HeroWidth = 10
>Set HeroHeight = 10
(HeroLength, HeroWidth, and HeroHeight are all integer variables)
<<<NOW THE ACTUAL SIZE CHANGE>>>
Events -
>Unit - Paladin 0000 <gen> Gains a level
Conditions -
>NONE
Actions -
>Animation - Change Paladin 0000 <gen>'s size to (((Real(HeroLength)) + 100.00)%, ((Real(HeroWidth)) + 100)%, ((Real(HeroHeight)) + 100.00)%) of its original size
>Set HeroLength = (HeroLength + 10)
>Set HeroWidth = (HeroWidth + 10)
>Set HeroHeight = (HeroHeight + 10)
I haven't actually tested it out, but it should work. In this case, the Paladin will get 10% larger everytime he levels. Of course, you can adjust the numbers so that he only changes his length, or so that he changes a larger percent, or etc. Of course, you do not have to use a Paladin, and of course, you do not have to name your variables as I did. Good luck with whatever project you are working on!