This team build would be a nifty way to control the entire map, defend turrets, and punish the other team through assassination tricks.

Here's the breakdown:

Twisted Fate: DPS Carry or AP, using twisted fate's ultimate to rush to any stragglers or team battles.

Pantheon: DPS, another teleporting ultimate. I think that Nocturne would be an alternate, as he also has a semi-teleport ability that could synergize VERY well with TF's ultimate clairvoyance ability to see all opponents on the map.

Karthas: Since this is a cheesy build aimed at punishing anyone who is solo late game, Karthas provides both AP mage status and can use his ultimate to finish anyone who gets away.

Shen: Tank. AND he can teleport to friendlies.

Teemo: Uses mushrooms to control the entire map. Mushrooms up their jungle so that you can quickly TP when one is in sight.

Imagine this scenario:

TF pops his ult to see everyone on the map.

You focus anyone who is alone and in a good position for destruction.

TF pings the victim.

Pantheon teleports after the ping. TF teleports to the exact location with a yellow stun card next.

Shen teleports to TF and taunts the victim.

If victim runs away, Karthas pops ult.

Instant gank anytime TF gets his ult. All heroes except Teemo might consider focusing heavily on cooldown reduction to facilitate as many teleport ganks as possible.

Everyone might also consider getting teleport as their special skills.