引用自 {λ}KhellStrix：

Pros:
+25 health on wearer
Cons:
-20% firing speed

well those stats do not make much sense. as a spy, you do not need much health and neither do you need to be able to backstab 100 times per second. maybe something like:

[pro]
Fills watch instantly if you backstab someone

[cons]
Watch only lasts 75% of its normal time.

pro-causes bleeding
con-hit yourself, idiot

[Pros] On hit: Causes bleeding. +10% firing speed (?)

[Cons] On hit: recoil for 5% damage. (?)

Suggestion, as it is called "The Backbiter".

Upon backstab user gains 50% damage reduction from all sources for 5 seconds
User cannot cloak or disguise for 5 seconds after backstab

25% faster firing speed
-25% slower reload speed

引用自 A Chef's Rice Pudding：

Upon backstab user gains 50% damage reduction from all sources for 5 seconds
User cannot cloak or disguise for 5 seconds after backstab

25% faster firing speed
-25% slower reload speed

ummmmm... slower reload speed?

+Gain Cloak On Backstab (10, 20, 30%?)
-Can't Slash (Only Backstabs)

[+] On kill: explode violently
[-] No random crits
On a more serious note:
[+] On backstab: Increased run speed for 5 seconds
[-] Wearer cannot cloak

引用自 EatLeDirt：

+Gain Cloak On Backstab (10, 20, 30%?)
-Can't Slash (Only Backstabs)

it would be worse than the big earner if those were the stats

Backstabs only do 50% of targets max health
on successful backstab gain 20% cloak and gain health based on 50% of damage you dealt

it will take 2 stabs to kill anyone

引用自 Retarded Spycrab：

引用自 A Chef's Rice Pudding：

Upon backstab user gains 50% damage reduction from all sources for 5 seconds
User cannot cloak or disguise for 5 seconds after backstab

25% faster firing speed
-25% slower reload speed

ummmmm... slower reload speed?

o_0 what!?!?!

+bleed on hit for 5 seconds
+damage increased by 20%
- reduce priamry weapon ammo by 40%

the spy now heavily requires on backstabbing opponents, rather than picking off targets with a pistol. is this good or bad plz tell me

Stats:

pros:
25% faster switch speed (it does seem like a small knife, at least, to me)
10% faster attack speed

cons:
on x3 miss: drop the knife
on backstab: enemy only loses 75% of current health

引用自 UltraXera：

+bleed on hit for 5 seconds
+damage increased by 20%
- reduce priamry weapon ammo by 40%

the spy now heavily requires on backstabbing opponents, rather than picking off targets with a pistol. is this good or bad plz tell me

not too bad; I'm not sure about the positives however.
neat concept though, gives more reason for being sneaky sneaky (stealthy).