This level starts with a brawl. There'll be some gold-armored goons in the mix, so Cpt Marvel is a good choice here.
When you've cleared the hostiles, smash everything. Some pieces stage right can be used to make a grav booster- activate it with Star-Lord to lower two jump ladders.
As Cap, jump up the ladders (because it would clearly be beneath the dignity of any of other three fliers on your team to give you a lift up), and stand on the pressure plate to reveal a shield receptor.
This activates a rune platform back on the lower level. Use Strange to solve it, a pattern you'll have come across several times before at this point.
Enter the opened room, and activate the rune there (no puzzle required) to open a portal.
Send someone technically minded through to work the console on the other end. Note also that, as the conveyor belt trundles past, there's a minikit on it you can grab (don't worry about missing it- it'll pass by again in a few moments).
Activate the console to take control of a defense cannon.
This launches a fresh wave of hostiles. Take out the ground-level ones the old fashioned way.
When they're out from underfoot, mount the defense cannon you just commandeered, and use it blow away the bots, enemy turrets, and the large central door on the upper level.
Cut open the gold panel revealed in that central door.
This lift takes you to Kang.
Your first fight is mainly against three large scissor bots. They're a lot less dangerous than they look- Cpt Marvel is a good choice for distance blasts and close range smashes here.
When they're cleared, start smacking around Kang directly. At this phase he won't do much, so just keep the hits coming.
When you've taken off about 1/5 of his health, his shield will go up, some holokangs will attack, and a portal will summon a charging Carnom. Hit 'jump' to get out of his way.
Stay away from the tentacle portals (always good advice) and use ground-pounds to nail the blobby symbiotes.
Kang will rejoin the fight with some ninja moves. Note that, unlike most charge attacks, Kang will spin all the way to the end of his red line, then spin back to his starting point. Plan your post-spin attacks accordingly. Also, like many ninja-types, this Kang is good at deflecting incoming fire, so melee attacks are preferred.
When Kang reaches 3/5 he'll pull the same tricks as before, this time with the spiked ball from Percy's palace. As before, jump out of its path.
Clear the medieval-themed Kangbots and re-engage Kang. His attack pattern is pretty the same as before, and beating him causes the same reaction, this time with Torg as the summoned charger.
Clear the goons and wait for the tentacle portals to close. Kang has adopted an invincible ninja-tumble this time around, so let him tucker himself out before attacking.
His last summon is a time distorting portal, but Strange is immune to it.
Switch to him, and timewarp the portal forward to give Kang a surprise.
This begins the next stage of the fight.
The layout of the bridge here is very similar to the layout of the generator room onboard the sword. Go to the upper level, upstage right control room, and burn your way in with Cap Marvel.
Smash everything and use the pieces to repair the slidey tiles, then push the energy core all the way down the path and over the edge.
Use the console that sprouts up mid-room to ferry it into place.
As Captain America, enter the holoprojector. Follow the onscreen button prompts to best MegaKang at his own game.
Winning this fight completes the mission, and game's main storyline.
I am almost always in favor of watching a game's credits, to pay a measure of respect to everyone involved, but these particular credits blue-screened my computer, so respect at your own risk.