Lucian has many things that hes good at but it seems like he has plenty more he is bad at. He requires some magor skill or a very good support to get fed and carry a game.

some of his pros are | some of his cons are
removes slow with E His e has a large cooldown
aoe damage hes very mana hungry early game
ult does more damage with more attack speed his ult only shoots one direction
can get early kills easy with passive is very easy to catch out and kill


Now why play lucian like this why not build him with phantom dancers and lots of blood thirsters. well only building damage can be good but it also hurts a champion making him useless with out other types of items to rely on.
if you ever have the chance to play with a soraka or a taric support they are the two best supports for lucian. lots of heals bonus cc (cause lucian has none).

not exactly blue Lucian but most of the items are blue. the reason i get manamamu is it allows Lucian to not be so mana hungry. last whisper allows you to hit harder with your ult. blade of the ruined king gives life steal and bonus attack speed making Lucian ult hit even harder. If your team complains saying your building Lucian wrong just keep going at it your build will start doing some kick *** damage. your ability's will do nearly true damage with last whisper and your passive will hit harder and harder the further through the build you go.