User blog comment:TheTobarMethod/Do AP's Need A QSS Upgrade?/@comment-4290320-20130903161424/@comment-15244341-20130905200835

More than being a hard DoT champion, Swain's problems lie in his harsh item dependence, ungodly mana-drain on his ult and, as any good Swain player can tell you, horrid match ups in lane. Simply put, Lux vs Swain is actually close to unwinnable if it's just a 1v1 situation with equal skill level on both players. No buts. But yes, he does fall of late game since he is more of a hybrid tank/AP caster than a pure DPS caster as Cassio.

Don't get me wrong, DoTs have their issues. It's the other stuff that makes Swain sweat much much more. With Zhonya's he can survive temafights pretty well and deal quite a bit of damage.