Hi! So regarding your question, it's basically a given to always run prowlers claw, just due to its mobility as well as its raw stats. However, if you are not comfortable with prowlers claw combos or just prefer the invis after duskblade, it is always still going to be a decent/safe item to build. It's just that prowlers claw is very broken right now, seeing use on champs such as like Renekton or Kayn. Duskblade itself is a good item for multikill 1v9 games, which are more often than not what you find in gold and below. The minute CD for prowlers can make duskblade the better option for some people, as well as the invis passive, especially considering how ARAM low elo is.

-Lucid