that's horrible

charge wont stop, when damage taken
+1 second longer charge time

cant think of any cons yet.

Pro:
Charge Wont Stop on Hit
One Hit: +10% °Charge°
+80% Charge Damage
Cons:
-50% °Charge° Charge Rate
No Critical Hit's while Charging
-10% Move Speed

I think it could be like this:
+ | +25% knockback force dealt by charge
+ | Upon hit: releases a wave, pushing nearby enemies away (but only damaging the one you hit)
(As all the shields do, it should have some resistances)
+ | +20% blast resistance
+ | +15% fire resistance
- | -25% charge recharge rate
- | -1 max heads collected by melee weps
- | -10% charge speed

The knockback ability would increase the demoknight's survivability, as enemies would not deal point-blank damage, but close or medium range. The slower charge recharge makes it less op, as with the normal rate demoman would (most likely) spam the knockback charges (f.e. on payload maps) to slow the enemy team down. Max heads decrease make demoman less tanky when using head-collecting swords, as at his top he'd have less health, damage and speed. And, finally, slower charge makes it easier for enemy team to take action against the demoknight.

Though I think the resistances given by the shield may be too low. I don't remember the Tide Turner ones, and they were the lowest, but I think they were higher anyway. Gaben, pls moderate my comment.

+ Hold Alt fire to ready and build charge
+ Use Mouse to aim at target before charging
+ Damage Resistance while holding charge
+ Damage depends how much charge built before letting go (15 min to 50 max)
- Start with no charge

If ya kill an enemy Medic in a "Crash" you get 25 or 50% of his Über as Charge.

- Getting a kill within X seconds of a charge makes you invulnerable for 2 seconds. Stacks for multiple kills in that short time.
- 25% slower charge rate
- Increased knockback vulnerability

you can hit 3 people after that you will stop
5% resistance to everything
it has 3 health -1 when hit by any explosives
gives a big knockback when hitting people
+10 health depends on amount of players killed with the shield
-20 health

Pros:

Immunity to Knockback
Immunity to Fall Damage
On Impact: Knockback on Target
On Impact: Stun Target for 4 Seconds
On Impact: Charge does not Stop

Cons:
-25% Bullet Damage
-25% Explosive Damage
-25% Fire Damage
-50% Sentry Damage

Special:

Incoming Damage refils Charge Meter

+20 max overheal on wearer
+20% health from all sources
+20% charge duration
+Charge doesn't end on impact with enemy
-20% more knockback from all sources
-20% more damage taken from all sources
-20% slower charge recharge

honestly, I think that, if valve were to follow the maker's idea for stats, it would probably be

charging into an enemy catches them on the shield
enemies take however much additional impact damage upon being slammed into a wall or pole (based on distance travelled).

+20% charge damage penalty (check out, valve labels all penalties as + #% (whatever stat) penalty

Pros
+While charging, you will continue to charge if you attack or run into an enemy
+Charging into an enemy deals knockback
+75% knockback resistance on wearer
+25% bullet resistance on wearer
+15% charging speed
+30% increase in charge impact damage

Cons
-User can only gain mini-crits from charging, no full crits
-no turning control while charging
-2 second max charging time

stats

+50% bash bonus

+ knockback is 2x the knockback of the force-a-nature

+kills with bash give 1 head (if the user can collect)

-no resistances

-50% of head collecting weapon kills don't give heads

(+) You cannot be knocked backed, slowed, or in any way be stopped by anything but a wall while charging.
(+) You don’t stop charging after impacting players, and will drag them with you.
(+) You don’t stop charging after attacking with your melee.
(+) Charge on hit/kill will extend the duration of your charge (This wouldn’t happen by default).
(+) Charging into a wall while dragging players with you will deal bonus damage to them.
(-) You only get 1 crit attack while charging.
(-) No damage resistance.

Thought it would be something fun to use.

Critique would be appreciated!

your second stats idea is rly good.use that