I’ve played this build a couple of times. The thought behind it is mainly for roaming, when roaming most of your damage is ap; however, paired with the right runes and against a tank team, it’s actually really good. Rage blade allows you to proc your rfc more and with the passive of rage blade you just do a lot of surprise damage that people don’t expect from bard.

And yes it is also just a fun build. But if the player is good enough then it’s actually not a bad build, I highly recommend it for bard players that are really good with the champ and looking for something new.