Attempt at a mechanic. Worth using on multiple cards? Can it be in ?

Is it meant to be worded like a replacement effect, or a trigger? At the moment it's somewhere between the two.

Replacement effect: "If this would leave the battlefield, you may instead pay . If you do, [remove all damage from it] and draw a card."
This runs too close to regeneration and probably doesn't belong in blue.

Trigger: "When this leaves the battlefield, you may pay . If you do, draw a card."
I would say that this version could indeed be blue or black, and probably green, too.

I did not know "would" was so significant in the wording.