Adds an stun to mana burn

I've read on a FAQ that you can add a stun to manaburn with triggers
but that's so homo because you can't add any buffs to a spell!!
I've done a spell but i want it to stun, but I can't add a stupid buff.
Or does buff really decide the stun or not! help me please!!

You're doing it all together wrong. The triggerwork you are refering to is not about adding a new buff to a spell (that's not possible, every and each spell has one and only one buff), but it is about casting two spells simultaneously.

It goes like this: when a player casts the mana burn spell, a trigger creates an invisible unit (with no model, shadow, whatever, and with the locust ability that makes it unselectable/invulnerable... so it appears as if that unit does not exist) and orders that unit to cast the stun spell. That way you get two spells for the price of one. Also add a few seconds expiration timer to the unit (called also the dummy caster) when it is created so that it dies automatically after the stun spell is cast.

Could you not simply have a trigger fire when thats run and pause the unit for however many seconds and then unpause it?

just exactly how do u make a nit with no model?

That's easy, select the model field. Choose to input a filename for the model instead of selecting a specific predetermined model and just press spacebar. Then hit enter. Bham, no model, a purely invisible unit.

Just use "Hide Unit", hidden units can cast spells perfectely well. Also you need to make the hidden unit at the position of the target to avoid turning/projectile travel time.