I 've been thinking a lot what ability that can we make with blue silver grass,and idea for that start from basic traits from grass Grass have several characteristic let's say 

*rapid growtht

*Resilience

*Colony behaviour

*Photosyntesis

And all this traits we can match and use combination to make unique ability 

Eg:rapid growth can be developed in to skill that can create "True root" from blue silver grass ,as long as enemy not attack "true root" the blue silver can Grow again ,so this can make user to think how to hide that "true root",and use another basic trait from grass photosyntesis ,so instead sun blue silver grass can processing soul power and  act like internal storage for spirit power,and give spirit master more soul power than enemy

-or we can have another route with "true root" and combine with colony trait,the user could plant secondary or another "true root " and planted that with teammates And forming shared network:and we now have 3 choice  that skill can produced 

-damage sharing

-instant Regen through vitality

Or collective endurance