Parrrley applies On Hit effects like Frozen Mallet or Black Cleaver.
Paying attention to low-health enemies on the map can land you a surprise kill with Cannon Barrage.
Try placing Cannon Barrage on the path of escape to cut off fleeing enemies.
Parrrley deals a high amount of physical damage. Items that grant Armor can help if an enemy Gangplank is doing well.
Once Gangplank reaches level 6, watch out for his global-range ultimate, Cannon Barrage!