So yes, the easiest way would be to poison it, but then anything with Growth is cheaper, for it also uses one quantum to get +2/+2 per turn, not +1/0. Poisoning it multiple times and healing, so Death/Light/Darknessemark to play Parasites, would yield even to +5/0 per turn, but then it's pretty... hard to pull off, such a complicated combo... and the enemy just wouldn't be damaging this and have peace. I'd say this card isn't very useful, but could be put in some rainbows just to have them there for an equivalent of 4-5 pillar produce and maybe somewhen it'd gain some attack.
Still not very useful without some combo.
The Rage Potion idea is nice, though.