You should leave lane to stack up your passive when your wave is pushed in and you can't do anything to the enemies.

Your Q (Cosmic Binding) stuns if you hit 2 enemies or if you hit an enemy+a terra

Your W summons a little shrine that will heal and speed up a teammate that picks it up.

This ability right her is the most enjoyable bard ability. You create an one way portal that goes through walls

Your ultimate ability is an area of effect zhoneas for whoever is in the circle.

To start off the game you can take (Q) or (W) first. You can start if your jungler is starting bot side and does not have good clear/sustain. If you started first i recommend trying to go aggressive unless your support can't follow up with your stun or the enemy adc is stronger than bard.If you started , just put a few of those down in your jungle for your jungler and just stay behind in lane and farm up.

During the mid game you should have at least statik shiv+phantom dancer or infinity edge already so you should be focusing on trying to catch enemy adc alone in lane and stun him. After you stun their adc you should be able to 3-5 shot them as long as you're not too far behind and they don't have anyone to shield/heal them.

During teamfights, just stay to the side of the fights and look for opportunities to land your on the enemy carries and focus them down. If you are not in position to do this just stay behind your team and just focus down whoever is closest to you.

+pros
High Burst
High Mobility
Unexpected

-cons
Squishy
extrememly reliant on landing your
Really Easily Countered