At my level (mostly rank 4 legendary mechs) , Volti is only a menace in hangar showdown. And yet even there I am learning how to deal with it and in fact these last few days have had a greater than 50% success rate against it. 

I think in the current game nothing is so OP that it needs a nerf. The only exception might be compound beams. Not sure about tailsting since I haven't faced it much.

Have you got a decent amount invested in canopy mods? Have you got seeker? If the answer to one or both of those is yes, your experience with volti will probably be a lot different from mine. Also seeker is super braindead itself.

Hangar showdown is already luck based most of your matches are going to be a tossup anyways

Even still SP tankers use it too.

Volti using SP tankers are among the tougher SP tankers to kill because like I said before Volti can target stuff with its ability through walls. A damaging ability. And it's not a teleporting ability like seeker so it takes exactly 0 risk to itself. And it can be used at 100+ meters.

You say there's nothing too OP that it needs a NERF but I say nothing, and I mean NOTHING, should have a 100+ meters damaging ability that can target opponents through walls. It takes 0 skill to use and you basically get tons of free damage.

Or maybe they should rework volti instead so it applies the oracle status effect to itself when it uses its ability so it becomes much easier to locate and flush out of cover.

Volti needs to either not have its ability go through walls, have its range NERFed, or have some kind of punishment for using its 0 skill 0 risk free damaging ability

You make some good suggestions to temper the ability. But as long as it stays the way it does , I'm just saying it can be dealt with fairly decently. In hangar showdown I'm actually at league 3 so no mods and I don't use seeker. The main idea is to try and stay unseen (avoid the "detected" eye) for as long as possible and use a fast mech to close the distance at the right time. Fast mech can be with the help of charge rockets also. It's not foolproof but my rate of success has improved lately. Mechs I've used recently with success include outlaw, Volti itself, vortex and parasite.

Outlaw will always be my top5, parasite will probably be my choice when i get it, vortex is a good tank.. volti is ok.. but its not very fun, its slow and boring.

See I have to try and not be seen while worrying about their teammate and traversing the map and whether or not my teammate will sabotage me and get themselves killed while volti can just try and not get seen while sitting right where it spawned

Yeah you CAN beat it semi-reliably. But it doesn't make it any less of a nuisance.

Also the mechs you say you've found success with first of all they're all legendary which I have a couple of those but they're expensive. But also one of them is another arguably problematic camping mech and the other is the devil himself. And the other two are damage reducing tanks which are generally effective everywhere

I'm not an expert in game balance I would say. But what I do know is a game is generally considered unbalanced when one of the few ways to successfully counter something is to use that thing.