Kiora's main weapon is her minus ability, which can trigger some very strong combos in Modern.
The most obvious one is the Utopia Sprawl synergy, which could be triggered twice a turn, if you also run Arbor Elf. That's a lot of ramp on turn three!
A deck that maindecks Kiora would also want to run creatures like Tarmogoyf, Grim Flayer, Knight of the Reliquary, and Thragtusk. All of them could enter the battlefield with four points of power triggering Kiora's passive ability, which would draw you cards for free.
All this can guarantee a pretty solid run for Kiora in such well established archetypes like Ponza, Titanshift, and Elves.