These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: Warhammer 40,000: Chaos Gate
Anticlimax Boss: When you finally meet him, Zymran is a pushover for your Terminators, your heavy weapons or even your Assault Marines. He has pretty much the same stats as an elite Khorne Berserker and uses the Power Sword instead of the more powerful Power Fist. The Chaos Terminators you have get through before him are actually stronger than he is.
Both Greater Daemons as well. The avatars of dark gods of cunning and rage, monsters who can supposedly wipe out entire armies and devastate planets, fall in a single turn to your Terminators. Even moreso the Bloodthirstier due to the Boss Arena Idiocy (see the main page).
Demonic Spiders: The Flamers. They're tough and fast, can set your guys on fire (meaning they take damage and lose turns until it goes out), cannot be set on fire themselves and, worst of all, they will almost certainly set you on fire if you try attacking them in close combat.
Game Breaker: Quickening. Gives the already deadly Assault Cannon even More Dakka. Has been known to wipe out entire squads in a single turn. Also doubles the number of blows your marine can land in close combat, making the Thunder Hammer bearing Terminators ridiculously powerful.