Immortalising a tree wouldn't save them (have you not tried quinting a poisoned creature it still dies) in fact quinting it would be sending it to its death as then you'll not be able to play any buffs on it or rewind it......maybe it should just be immortal 
Oh no, I meant the sapling - if it continually increases in it's HP but loses attack EVERY turn, then eventually, it'll get something like 25+ hp and -15 attack, which means it's healing you while gaining hp, and you can't take it down if you wanted to if it's Quinted.
For the elder tree, yes, you'd send it to death if it was affected by Quintessence.
I presume you're on about quintessencing(?) an enemy sapling otherwise it'd heal your enemy and hears where you hit a dilemma I've had many times with ferox and fire queen. We're on about the element with bonds if you quint a creature on there side despite it healing you it will still be continually healing them depending on how many bonds they have out it may even start healing them 6 per turn and there's nothing you can do about it. This does also mean it'll be healing you more but still worth pointing out.
You're also on about the deck which is associated with rush and if the rush is pulled of appropriately then you shouldn't still be trying to win by the time the sapling gets into the negatives (thus healing your oppopnent).
Oh, that makes sense. So initially, using Quintessence on an enemy creature too early will still net the opponent more healing while the player will take more damage over the first 10 turns (assuming the rush hasn't already whooped the player at the start). I
think I understand what you're saying.
(Of course, using Anti-matter and Quintessence on an enemy's Sapling simultaneously would grant the player healing at a possibly much greater rate, but that's an academic circumstance.
)
It's still an interesting card with lots of potential uses with the alchemy cards (for good and bad), but it can be situational (too situational for a false god to use, in my opinion).
