10. The Warden Eternal - Halo 5: Guardians
While Halo 5's campaign is a relatively standard fare exercise for the franchise, it's enjoyable enough for the most part. Except, that is, when you're forced to face off against the game's big bad, the Warden Eternal, three times throughout the story mode.
This wouldn't be so problematic if the Warden wasn't a generic, featureless antagonist who amounts to little more than a damage sponge during this trio of repetitive encounters.
Players have to attack a weak spot on his back while also keeping the Warden's cronies at bay. And because the only way to ramp things up for the finale is to give us more, the third encounter with the Warden sees the player fighting him in triplicate.
Needless to say, it's annoying enough on a manageable difficulty, but if you're brave enough to give the Wardens a go on Legendary, you might want to pre-emptively invest in a new controller first.
Were the Warden an interesting villain or were these engagements clever designed, then the ramping wall of difficulty wouldn't be quite so maddening.
But ultimately, he reeks of a woefully unimaginative final baddie thrown together during the game's infamously rushed development.
Re-playing Halo 5's campaign already wasn't a particularly tantalising prospect, but this near enough sealed the deal. Thankfully, the typically superb multiplayer suite still makes the game well worth a buy.