Tengu was my favorite, but since the last update, there seems to be a glitch in which despite jumping before the charge emp hits, the tengu still gets stunned, but weirdly just gets sat back down gently in the prejump position. My general counter is keep plenty of distance between my mech and surge, like double basic charge distance.

Attack Surge from behind. Besides, it's not immune to other Abilities. System Crush or Shock Pulse can prevent it's attack for example

Best options are Guardian, Eclipse, Aegis and Bastion (with shield on). For a F2P player it would be mostly Guardian and Aegis. Guardian can cancel Storm Dash, Eclipse doesnt get affected by it (a fight between Surge and Eclipse is more about who hits the other one first), a skilled Aegis player (me) knows how to stop Surge with the Dome, and a Surge would be stupid to dash into a Bastion that has his shield on because breaking it would result in the Surge also getting stunned.

Zephyr can't beat Surge (unless he ambushes it) because if they both activate their ability at the same time they both get stunned, only Zephyr is stunned for a longer time while Surge is stunned for a shorter time.

Yes for sure the best option is eclipse. I don't have bastion but I do use surge and with bastion it's damn near impossible to kill him with fragment guns which is what most surge users me as well go with. Now I  have eclipse and I'm immune to panther wall empd the works. So I let those surge in and made nuke them to hell. Quite funny cus most times you can see from their slower responses that there mind was trying to undertand they are about to die and I wasn't empd for a ninja kill. also I use redeemer now if timed correctly you can let them waste it when u see the dash or if you can tell they are priming for the dash. It's a skill / guess sometimes I phase and they surge after but I have timed it perfectly plenty of times. . Now often their cloak is gone and they at least wasted 1 or 2 shots firing trying to shoot at me. Also cheetah is my little shit head I wish I had a skin that made him look like an antagonistic prick that I love him for. like a clown or something anyways. With cheetah like most of my lineups I use overheat beam weapon when you know that surge is near pop down ur mines then antagonise the surge player overheat it shoot and play cat and mouse. If properly irritated he will jump into your 3 mines with overheat. Or use surge on surge I do this to eliminate the surge and sometimes my weapon is bigger or theirs is but now it's a weapon response thing. because tbh most players are cookie cutters and once their "good" mech is dead well it's a compromise and risk I'm willing to make if a mech is dangerous enough I'll self sacrifice for the good of the team. But then again your teammates have an opportunity to kill it or them me. I also use 5star tengu I'll wait behind something or go from above and aim for behind the surge. Regardless the freeze will not let him turn to emp me unless he's looking at a wall. But with added freeze he's emped me but can't turn fast to actually utilize his ability. The best way to learn surge weakness is playing with him and what messes with me in order of danger level. 1. Bastion, 2. zephyr, 3. Guardian,  4. Eclipse . I forget the name of the mech but it's power holds you and it's a purple swirl I know that one kills me but since I don't own one I don't have enough info to be entirely but I do know they do kill me and often times it's with em rifle.

I hope this helps and hope your not a free player because this wouldn't really help you much. But maybe someone might. If you want to get better at these ideas or try them fast buy tickets and play the FFA it is so much fun even if you lose or don't own it up. It lets you use try tactics die over and over even the same mech depending on how fast you die again. FFA helped my gameplay a lot. I wish there was FFA tbh that I could play constantly without tickets and without tourney because I love it that much. Anyways that's a thread all in it's own. Happy hunting

Surge very irritating. I hate surges. I always try to kill them first. Death to all surges... lol

You recognize the power of redeemer I see. Good for you.