FIX #1: NAAP

Putting out an Errata for Spiral is easy (they do it with every set, so this is no different). With that, some version of NAAT would work very well.

What is NAAT?
Back in the old days, a character that was carried (aka taxied) could be given an action. This led to a much faster game than what you see today -- Superman could carry Wolverine across the battlefield, and on the same turn Wolverine could immediately make an attack. This all changed when IndyClix was created, pretty much because IndyClix only contained 2 characters with Flight.

Wizkids made the wholesale change to the rules because of 2 little characters and this new rule was called NAAT -- No Action After Taxi.

Bring on NAAP!
What I propose is a No Action After Portal. The new Spiral Trait would work like this (new text in blue):

DIMENSIONAL PORTAL: Give Spiral a double power action, remove all Gateway markers from the map and place 2 Gateway markers on the map. Place one in an adjacent square and the other may be placed in any square on the map. Friendly characters may treat squares with Gateway markers as adjacent to each other for movement purposes. A character that travels through the Gateway markers cannot make attacks or use any actions after their movement ends.

And just like that, balance is brought back to HeroClix. Spiral's power is essentially unchanged, but the usage is modified. You can still use Hypersonic Speed to enter the portal or simply move through it, but you can't make any attack afterwards, even as a free action! 

This wouldn't nerf powers like like Poison, but it's not supposed to.