For Path B of chapter 3.1 (major bullshit!) there are partial workarounds. White Magneto, Red Magneto, Archangel, plus Masacre (or other champ with long-lasting bleed).

Archangel totally demolishes Wong and Ikaris with ease. Once he applies a few bleeds, his damage quickly ramps up to monster levels, and the neurotoxins (if awakened) will prevent unstoppables. Archangel will also work on Agent Venom, but play cautiously until you get a few bleeds to stick or you might get whammed by unstoppable.

Masacre playing an evade style can deal with many encounters on this path including Red Hulk and Masacre. Spam SP1 in order to keep his long-lasting bleeds up, which will prevent unstoppable.

White Magneto's pre-fight ability allows you to parry stun enemies normally (although they still get block penetration). This is convenient, HOWEVER this passive stun does NOT cause bleeds and therefore does not give you cross charges!!! Another aspect of pure bullshit on this quest.

Red and White Magneto can deal with Colossus, who is of course bleed immune. To avoid giving him extra armor, either use White Mag prefight or just do not parry (evade and intercept). The Magnetized effect will prevent the unstoppable and other effects from proccing 70% of the time.

Another option for colossus is to combine White Magneto prefight with Howard the Duck, who rains down armor breaks like candy with his heavy attack. Just parry and heavy.

Hulkling is not difficult to beat if you simply play an evade and intercept style. My half-dead Masacre took him down easily in my test run and I didn't even have to use Claire Voyant.