Power of the Swarm:
If Essence Collection hits a hero, Niadra or her Host will become empowered for the next 4 seconds and deal an addition 15% to enemy heroes
Strength of the Swarm:
If Essence Collection hits a hero, Niadra or her Host will become empowered for the next 4 seconds and have damage reduced taken by 40%
Speed of the Swarm:
If Essence Collection hits a hero, Niadra or her Host will become empowered for the next 4 seconds and have movement and attack speed increased by 25%
These talents will help differentiate the play style for this hero. Do you want help increase the damage for mages? make your tanks harder to kill? or increase the damage of your AA heroes? The numbers will need to be played around with for balance. Ideally all three options would be viable depending on team composition.
Here have a plus :D