Today's a special event, a gold portal with the reward of 200 (!!!) total tokens if you clear all 3 difficulties.
Since the insane difficulty is what mostly everyone will have issues with, i decided to make a small reference point for those who want those 100 reds.
Below are the 4 mechs you will encounter in this portal, 2 buggies, 2 tanks, 3 mechs, and Roaster.
150~ Cooling / 150~ Regen on buggies.
200~ Cooling / 200~ Regen on tanks.
250~ Cooling / 250~ Regen on the mechs.
275~ Cooling / 250~ Regen on the boss.
Here is the mech that i used to clear insane, without a revive:
Here's a more free to play version that should work just as fine:
You could also use a boiler, or a physical mech to brute force with damage, but i prefer energy more for these portals as it disables their weapons.
Good luck!