Quote Originally Posted by Lyrinn View Post
It's not a matter of being able to survive and let the situation rectify itself. There are literally zero - Z. E. R. O. - reasons to pre-cast a Medica II or use during a pull. Please, by all means, do come up with a valid reason. I would love to hear it.
Snowcloak, first(?) boss, where he has the AOE's and frost bombs. Good pre use of medica II can cover for if the healer gets frozen. Can allow slightly weaker healers to catch up easier by having that extra HoT ticking over.
T6 - Cast a medica II before the second vine set, deals with damage occuring by people being silly and running the same direction with vines, also makes topping up the damage from spit slightly less panicky (pre-nerf this was a godsend, post nerf, not too much of an issue, but still there.)

Don't get me wrong. I'm not saying spamming this as a given before every mob is right. It's definitely not, tank pulls hate > healer waits for the aggro onto tank, THEN heals, but, there are certainly instances where using medica II before or at the very start of a mob/ability/expecting more mobs soon is useful.

source - mained WHM for ages.