Ehm no.
Using the Dematerializer grants you once 4% Bonus DMG against the the type of minion you absorbed. Absorbing anohter minion of this type increases this bonus to 5%. The third: 6%
If you're using all 6 on Melee-Creeps, you deal exactly 9% DMG to Melees, 0% to Casters, 0% to Cannons.
9%... In times of Static and Titanic...
If you split 4/1/1.
You deal 7% to Melees, 4% to Casters, 4% to Cannons.
That's it. Nothing beyond. That's 5% more waveclear. Noone with waveclear will use it. noone without waveclear becomes the next Anivia.
OK, SOME Champions are balanced around exactly NOT One-Shoting Casters at certain AP-Levels. Lux comes to my mind. And YES this Rune could barely be enough to change that.
But outside those shenanigans... noone except desperates Threshs will use it with success.