Infamous 2 gets some DLC with the Festival of Blood. In the new DLC Cole somehow gets captured by vampires and is used to resurrect a vampire queen. He gets bitten and has to chase down the queen and kill her before he becomes a full vampire himself.
The DLC takes place in New Marias around Pyre Night (a sort of Mardi Gras/Halloween). You’ll get some vampire powers like flight, and ability to suck the blood of civilians to gain power. The morality system is eschewed in this one and Sucker Punch just has you chasing down the queen at all costs. The story is told by comic relief Zeke to a lady that he’s trying to pick up in a bar.
For DLC it’s pretty stand-alone. You don’t need to have played Infamous 2 to get into the story or the fun of Festival of Blood.