Merc type = Recon
Ability= A single use medium cooldown (30 secs, would take playtesting to balance properly though) portal that allows the teleporting of mercs both ways. This portal must have both the sending and the receiving end placed manually and whenever the portal is used it takes damage equal to the amount of health of the merc transported. It has 200 health so it would only allow a Rhino to be transported before immediately having the receiving end break. Also the Portal can easily be damaged by enemy fire. This also means it would be a quick escape for low health mercs, but not too quick, like a 3 second interact time. The way of balancing this is the Portal would make sound audible to 10 metres at all times and send a beam of light into the air whenever used, along with a loud audio que.
Playtesting would be the only way to determine what this merc needs in terms of health and weapons, but I would hope for a high speed. This would be such a deep mechanic to add to the game and I think it would add so many layers of strategy to the game.
So, whadya reckon?
EDIT; I would just like to say that I hesitate to post anything further but shall do so anyway as this is my 69th post and I have a dirty mind.