I'm relatively new to the game, so I can't say this for certain, but I think that having such a low mana cost creature that can always move up to two zones every single action phase no matter what under any conditions is a bit OP,
Except that he cant always move up to two zones every single action phase no matter what under any condition.
It has to be a round that the mage paid a mana to activate it.. and if yorue running 4, thats 4 mana you have to free up every turn to accomplish..
And thats saying there isnt a supression orb on the table (making him pay another mana per move action..so 2 more mana per Gremlin per sprint)
or assuming that the Gremlin didnt get enfeebled, making him slow... which essentially means he can pay 1 mana to not be slow every round.
or assuming he has a clear path to run... he can teleport through walls, but if he enters a zone with a Hellfire Trap, Teleport Trap, Mangler Caltrops, Spike Pit, Poison Gas Cloud, and so on he still triggers those things when he enters the zone, before he leaves it.
They also wont last long with Chains of Agony hitting them for 2 damage everytime they rush.
Also, he is still subject to Guards when he gets where hes going.
Mordoks Obelsk will make it difficult to pay for their speed-a-port ability to, when you have to pay an upkeep just to keep it on the table and another mana to trigger it.
So, its not exactly a free ride and theres obstacles out there that can still hamper them.