How about Mana Burn?

[Vomitus]

I think it would be nice to have a purchasable 'trap' that acts like Mine but it only drains all your mana on activation.

We could call it 'Static Field' or smth else:)

Price: 100-300
Radius: 300-600
Items-in-the-pack: 1-3

It may work like:
- a mine, that disappears after activation
OR
- a token, that stands invisible fixed amount of time in one place and drains all mana of all enemies that got inside radius.

It also can be done as single-targeting item with multi-usage but it could be imba(either too weak or too strong, I didn't think about it yet), but I personally do not like this idea much.

Such thing can be used against port-in-port-out tactics(especially against Inferno).
And I think you could find many more

[Tribulation]

I really don't like the idea, especially since you suggested draining all the mana, that would make cp or base camping easier, which I oppose. I don't like the concept of mana burn for BT, I don't believe it fits into the game. For DotA it's alright, as that game focuses a lot more on a big mana pool and mana regeneration, but BT does not work that way, you don't even have enough mana to cast 2 spells at certain levels (HT's ultimate and Rocket, for example).

[JpOO]

Maybe it will be good to add some items with mana burn for 1 or 2 casts. But it should cost freakin' much. Like for 1 full mana burn at 800 range it should cost 4000 gold, so players won't use it often.

[Tribulation]

Well if it would cost that much, it would be pretty much useless, and can be left out altogether.

[Vomitus]

That's right. If it'll cost 4k-6k per permanent item with decent cooldown(40-60 seconds) - it will worth it.

[JpOO]

Well if it would cost that much, it would be pretty much useless, and can be left out altogether.

Maybe it is a really big price, but I just wanted to say that this item shouldn't be used like in every game by every player. Even not in every game by one player. It should be used like.. em.. teleport breaker.

[kittyonmyfoot]

I wouldn't mind a buff to the ghost tank's mana burn but a separate item? ... as tribulation said... either too weak to bother or severely imba... As far as port in and port out tactics... just surround a tele breaker with mines... that's what I do. It'd be nice if the tele breaker worked both directions as far as origin and destination (currently just works on destination).

Edit: I wouldn't mind a feedback item or ability that works only on the board cannon.