The question's simple: can I add a working invisibility weapon to my custom sith hero? I tried it with no success. (I took the stock bothan invisibility weapon and modified it a bit; it worked with a normal unit) So I guess it's not possible. Is there a workaround at least or should I not bother with it?
Thanks in advance.

Did you put all the .odf files and .msh files related to this weapon in your custom side's odfs and mshs folder ?

It's may be the problem.

Yes, as I said it worked with a normal unit of my imp side. (The invisibility weapon is only one odf actually.)

Look at the force power called something like "com_weap_inf_force_mindtrick".

the invisibility gets turned off if you take damage. hero's health decreases constantly. there might be an odf line to help you.

Just last week I tried to make invisibility work for my hero, with absolutely no success. I checked the odfs for the hero, com_hero_default, com_jedi_default, com_inf_default, etc. I couldn't find any way to circumvent the fact that the constant decrease in health will turn off your invisibility. As far as I know this problem is unsolvable.

But please let me know if you do find a way to make it work!

The mindtrick odf is also a normal invisibility weapon,so it wouldn't work, but:
What if I made a 'disguise' type weapon which replaces the player model with an invisible/mostly transparent model?
I also noticed that for an AreaEffect weapon 'mindtrick' can be given as an EffectType. I don't know what that's about, I'll look into it and find what I've got.

it wouldnt matter if the enemy was invisible to the human eye, the ai would not know the difference. but you could do that AND move the player onto a team neutral to the enemy with some lua commands. Its been done before with the disguise kit LUA weapon for bf2.

So it was a LUA weapon? Because there is a weapon class called 'disguise'. I assumed I could use this (that it tells the AI not to see the player), but thanks for the info. It's not very important, I can give my sith assassin another weapon, but I'll experiment a bit.