Although nicely drawn already, in my own perspective of usefulness it's really hard to imagine how a bunch of bones are related to abilities or tech-tree upgrade.
You could try focusing in one way, making it to looks like a proper item with darker background and different variations like one bone, few bones and finally this.
Similar suggestion can be applied on tech-tree ones.
If you insist going on ability, trying replacing some bones with better effect like dark runes or whatever it fits.