User blog comment:Lesdin/Adara, the Calamity Adherent/@comment-24385282-20161011032829/@comment-27802145-20161011052849

Yes, Adara's ultimate was intentionally made to not scale linearly.

With mobility in general not scaling linearly on a lot of champions, I thought it necessary for Shiva's Decree to function like this, as its primary function is to allow Adara to self-peel.