Angelica x Tiberius / A'mu
As adorable and classic as these champions are; with the recent low play rates and simple mechanics, I believe Annie and Amumu should be next in line for some reworks of their own. However, with the amount of total overhauls going into champions, why not take it a step further? The game has been going strong for the last few years, and with seven years behind us, we should give our beloved young chaps their coming of age into adulthood. Another trend within the development department seems to be the introduction of new sub-classes such as Juggernauts and Bruisers. (formerly just tanks)
These two champions along with a couple others, such as Blitzcrank, Kayle, and Ryze; seem to fit into a sub-class of their own, and would certainly excel on the rift if these underlying mechanics were further exposed. This could also give Ability Power-based champions a little more spotlight on the rift, and open up new paths to itemization and overall mechanics of the magic sub-classes.
As corny as the names in the title may seem, I just wanted to present an imaginative visual within the minds of the readers to give them the chance to see these two champions in a new light, with more serious personalities and potential for some amazing gameplay. Just imagine a more mature Annie with a battle-scarred armored bear, ready to take on Voli himself if he dares. Also, imagine our favorite sad little mummy breaking out of his shell (or bandages) and unleashing his wrath upon unfortunate souls.

TL;DR Total reworks and maturing for Annie and Amumu; give Annie more control of Tibbers and Amumu something more creative to do with his bandages. (if they remain in tact at all)
P.S. FAN ART PLS (I suck at drawing)