The fang of Apophis: A family Heirloom

[Nosta]

so my gm just gave me a pretty cool weapon. Its a pitch black short sword, highly detailed serpent like images on it. its a proof of ones ability to rule from my family and comes from my great great grandfather.
I am going to be allowed to used in search of my own proof of rule. The weapon is as follows


+2
Acidic
its main ability is once it cuts its foe it gains bane for that type of creature
and once perday as move action I can remove the bain ability to inflict 2d6 ability damage to all the target this can only be done with another suessful strike. but its 2d6 to all its stats


I just want to know is this good and is there any badass monsters that a roll of 10 or more will knock out or kill?

[frogglesmash]

Assuming you mean 10 or more damage to an ability score all dragons ever, also any creature with animalistic intelligence.

[Malimar]

There are very few creatures that don't have at least one stat at or below 10. Most commonly it's int or cha. So yes: damage to all ability scores is instant victory against virtually any monster if you roll well enough. Even if it doesn't kill or incapacitate a foe, you're still nerfing their tohit, damage, hit points, AC, saves, and save DCs all at once. Very powerful.

EDIT: There are some creatures that are immune to some or all ability damage, such as constructs, undead, and abominations. These are the only kinds of creature that this isn't very powerful against.

EDIT 2: I decided to do some investigation. Out of almost 2000 monsters in my master monster document (not counting true dragons, for reasons, but dex damage wins against most of them; also not checking for ability damage immunity):
10 strength damage incapacitates 289
10 dexterity damage incapacitates 375
10 constitution damage kills 122
10 intelligence damage incapacitates 1031
10 wisdom damage incapacitates 373
10 charisma damage incapacitates 900

More than half of creatures can be defeated by 10 intelligence damage alone.

[TheYell]

When you run the numbers you dont fool around! kudos for your skills