Try to play passively, quietly farm up, but poke with your Boomerang and Arey! Try to stay as long as you can because you have second wind and Doran's shield! Win the trades up top and you are set.

After you killed top's first tower, start roaming near mid and bot. Join team fights only when in mega form! When in mini gnar form, kite as much as you can without dying. Your rage will build up and soon enough engage with WQRE in a 1v1 against ap.

Try to attack the towers and inhibs as much as you can to end the game. Do not focus on kills, just damage champs so your team can sweep up. Always stand in front if mega gnar when in a team fight. Prioritize enemy champions with ad so later, you can kill the rest of ap champions.