Give Assume Aspect another function when EVOKED that gives you the properties of a tree. The tree properties include giving bark like skin (which occasionally grows acantha leaves) that serves a number of purposes. One of them is additional critical AND damage padding. A bit of each. This is the natural result of thick bark and sap with leaves, the trunk hardness underneath which is what your muscles and skin are now like. If the critter attacking you uses an edged weapon it may sometimes become stuck in the area they hit and eventually fall to the ground from the Ranger's movement or be removed and retained/dropped by the Ranger. Secondly, it gives the Ranger a bonus to hiding since they will more naturally blend in with the environment. This will give a +5 to Camouflage when this Aspect is running and give the following options while in hiding. SHAKE shakes you tree limbs a bit to startle and distract the enemy which will disorient them and give a stance raise, a bigger push-down, some other advantage. SQUEEZE will drip sap onto the weapon for one strike and will coat the wound of the for hit with the strike in a magical sap that restricts their movement and their healing in that area. GRIP will use their wood magic to make incredibly strong pressure using their grip around their weapon which results in greater physical force being applied to the next attack, increasing critical damage. Also a +10 to DS running.

It's different from Assume Aspect a lot but perhaps the spell could be updated all around. I had it with my Ranger in Platinum but am not using it with my Ranger Moondream now (don't play Plat now). Assume Aspect was not usually worth the mana for me, frankly. I felt it was under the bar for impact from the spell though it had a great overall design and the implementation otherwise is nice as far descriptions, options, etc.

I like all of those.

And, of course, you could combine flora with fauna, and Assume the Aspect of a spicy sushi maki, and roll with the attack.
<rimshot!>