My problem with Surgeon's Knife/Scalpel... I find it very overpowered. (Peoples prob like that). The mutated ability cost is dependent on the creatures color. Meaning that... since you are not actually mutating the creature just adding a random skill it will ensure that you can use the ability. (Which is not true when using mutate unless you are using a rainbow.)
Meaning you have a VERY high chance of gaining very strong skills (Scavenger, Immortality, Lycanthropy, Devour, Destroy, Steal, Growth, Freeze, Deja Vu, Immaterial, Dive) and be able to use them 100% of the time (not to mention 0 risk). Even when considering the lesser skills in the mix (Burrow, Ablaze, Mutate, Infect, Gravity Pull, Momentum, Psionic Wave, Poison, Heal) it is overpowered.
I don't know how you'd balance something like this... Increasing cost doesn't help with 100% assurance that the ability is usable. You'd have to edit the skill choices that could be gained. Nothing gained could be OVERPOWERED like through actual mutate (there is 0 risk and 100% usage gained with this card and this card is REUSABLE/cheap)... e.g no devour, destroy, steal, scavenger, deja vu, dive, freeze and immortality. That would make the card a lot less appealing to most people but a lot more balanced (but still might be too strong).
Also keep these points in mind...
-Surgon's Knife/Scalpel costs the same as a Fallen Elf/Druid and deals more damage and is less prone to being killed/destroyed.
-Mutate (unupgraded) is more likely mutate the creature into a 5/5 or kill it.
-Butterfly Effect (costs 5-- is a one time use with a requirement and high skill cost)
I figure people voted on it because how strong the addition skills COULD BE without considering how overpowered it might be. I don't believe Surgon's Knife/Scalpel has a chance of ever being introduced to Elements. The idea is nice but the concept is already covered by a Spell & a Creature... That should of been taken into consideration when creating the weapon (voters should also look at that).