MCU: 10 Truly Insane Crossovers We Need To See

While Spider-Man 2 may not be the top of many critics' lists of best comic book movies ever made anymore, Alfred Molina's Doctor Ock remains a fan-favorite and one of the most notable villains the genre ever produced.

Earlier phases of Marvel movies often drew criticism for a lack of memorable villains (Loki aside); Abomination, Malik the Accursed, and, Iron Man 3's the Mandarin, failed to inspire fans with anything beyond indifference, or, in the Mandarin's case, scorn.

However, Marvel largely corrected this problem as time went on. Villains like Killmonger, Baron Zemo, and, obviously, Thanos managed to give the Avengers worthy and memorable foes to battle.

Unfortunately, since the Avengers usually win in the end (a universe-destroying snap here or there aside) many of their best villains met their ends too soon.

Though these villains may have left us before their time, nothing is ever final where time variants are concerned. The entire premise of Disney Plus' Loki series revolved around bringing back one of Marvel's most well-loved antiheroes. Now that the Avengers toppled Thanos, the only greater challenge they could face is a league of their old nemeses out for revenge.

The final battle of Endgame will be impossible to top unless the MCU dips into their back catalogue and summon every variant imaginable to defeat earth's Mightiest Heroes.