I was thinking on this line earlier, and its actually to me like Bridge from Below. Was Bridge from Below 'broken'? No, not really. Hogaak was/is. Was Bridge a card worth having in the game? No, not really.
T3feri is the same to me. What value does it add? It just makes the game worse.
EDIT: Should say, again from an objective view, T3feri is not worthy of a ban, however as I leave you all with your game I would hope the players would begin to look at what makes for a better subjective game for the most people.
T3feri and a few other cards, are not part of that world.