Every Arrowverse Crossover Ranked From Worst To Best

8. Heroes Join Forces

The second-annual Arrowverse crossover only consisted of its two flagship shows (Arrow and The Flash), but it may as well have been a backdoor pilot for soon-to-arrive spin-off DC's Legends of Tomorrow as it introduced heroes Hawkman and Hawkgirl, villain Vandal Savage and a large portion of the first season's plot.

It once again felt like cutting-edge television seeing both Teams Arrow and Flash unite to take on an unstoppable threat and this one was pivotal in changing the crossover format so that both episodes covered the same adventure - as opposed to two standalone offerings like the first. It also contained some great character work, particularly in regards to Barry and Oliver's relationship, and even introduced the latter's son William into the fray.

In spite of this, and that truly jaw-dropping sequence in which The Flash runs back in time, this crossover struggled to match the heights of the others. It didn't have that notoriously light-hearted sheen that we'd come to expect from superhero team-ups, as it was bogged down with a lot of plot threads that took themselves far too seriously. Moreover, important characters like Laurel Lance, Thea Queen and Iris West were given very little to do while the contrived Oliver and Felicity conflict was nothing short of mind-numbing - a particular reminder of why Arrow's fourth season was, by far, its worst.