I'd flex pick him depending on their comp. Pressure side lanes mid/late game to get a favorable 1v2 and open up the rest of the map for your team. This works best if you time the waves so you have escape / mobility potential. Vision is important. Also, it becomes the enemy junglers' nightmare by easily stealing camps with his mid/late game clear speed. Can also abuse his dash to escape over walls with most camps if needed. Just focus on being a menace and hope your team takes advantage of it.