Story related and cannot be missed.
This unlocks after defeating the Abomination at the end of the seventh episode, “City of Doom”. To defeat him, you need to stay on the floating platforms since Doctor Doom will be electrifying the cage in the middle. Abomination will come to you so just block his 3 punches and then counter attack quickly. Keep it up and use heroic attacks when they are available. He actually went down pretty quickly. Maybe he got zapped by Doctor Doom as he ran over to me? This fight was over in less than a minute.