Question about hex's stacking...

I was wondering if I were to cast sayyy :

Life Siphon (Hex)
For 22 seconds, target suffers health degeneration of 3 and you gain health regeneration of 3.
Casting cost: 10 energy
Casting time: 2 sec
Recharge time: 2 sec
Relevant attribute: Blood Magic

And an ally cast the same spell on the same enemy, would it stack? They'd take 6 degen and we would each gain 3 regen?

Thanks!

Edit: Well now i dont really need to know..but an answer is still welcome

I believe it would cast but it would not affect the target this is extremely hard to test though so...

The reason I believe this is because I used arcane echo with lightning surge and when I cast the echoed version on a target prior to lightning surge running out the spell cast but had no affect it did not even refresh the timer or anything.

On the other hand casting a low recast hex on itself or an enchantment on itself just refreshes the timer but I can't see how they could do that since the side effect for life siphon is dependent on who cast it.

the same hex does not stack.
if two people cast life siphon on 1 target, that target only suffers the degen and duration of the latest one cast. on the other hand, both necros will gain the regen but the first one only lasts as long as his duration would..

What happens when a character has two copies of a hex on them is that both copies are "in effect", but the hexed character only suffers the effects of the hex once. Thus, you can have 8 players with life siphon all cast on the same enemy, but they will only suffer as much degeneration as is caused by the highest-level life siphon on them. Each player that cast life siphon still gets the health regeneration for so long as their hex is in effect. Anything that removes the hex seems to remove all copies of the hex, though, so if it has an end condition(wastrel's worry, lightning surge), when the hex ends, it removes all copies of the hex, and if someone uses a hex removal skill, all copies of the hex are removed.

If you cast a level 12 life siphon on someone, and a teammate then casts a level 1 life siphon on that character, they will still suffer the 3 pips and longer duration of the level 12 life siphon- the only thing that the level 1 life siphon will do is give the caster 1 pip of regeneration. The order doesn't matter- both copies of the hex will be active for their duration(so long as they don't have a trigger when they end), but the hexed character is only affected by the one with the greatest effect.