User blog comment:ImperiexSeed/Supernatural Mysteries/@comment-4281787-20120313203925/@comment-3045936-20120313222426

http://supernaturalwiki.com/index.php?title=Cambion they state that Cambions like Jesse are more powerful when Lucifer is free. This lineage makes them incredibly powerful and with Lucifer on the rise, they become more powerful, so powerful they are capable of "killing the Host of Heaven with one word" according to Castiel.