"A sudden rise in global terrorist attacks by U.L.T.I.M.A.T.U.M. has been effective at keeping S.H.I.E.L.D. busy... perhaps a little too busy. What started as a series of seemingly random attacks now feels like a systematic exploration of S.H.I.E.L.D.'s responses, like pawns testing an opponent's defenses. It's time for the Avengers to assemble, as a familiar foe makes his calculated rise to power, threatening the world." — Chapter Briefing
"The decision to leave the Hulk behind to defend New York was already debatable, and after this, the cons may forever outweigh the pros.
Mission 2 contains an Epic Boss Event, available only once Task 25 has been completed. Complete Task 25, return to Mission 2 and complete all Deploys and combat events to reveal the Hulkbuster versus Hulk Epic Boss Event!" — Mission Preview
This is the first Special Operation that does not have a reward hero, but instead an alternate uniform.
Whilst fighting Ultron Sentries in Mission 2, there is a chance for Hulk to appear in the battle, meaning the player will have to fight him too. Hulk cannot be KO'ed, similar to Mephisto, he will flee from combat.
In Mission 3 Boss, after mid-battle dialogues, Vision will defect to Ultimate Ultron, counted as KO'ed, affecting PvE Score Modifier. His stats will not share any bonuses of the player's Vision like Iso-8, Empowered Iso-8, and Augmented Iso-8, and will not be based on his level.
Summoned Ultron Sentries do not retain their passives.
Ultimate Ultron in Epic Boss will flee when max Health is below 50% and cannot be reduced below 40% of his max Health in first wave.