Early Rounds: Activate Goblin (3) Synergy effect with the pieces that cost the least Gold or deploy other 2-star pieces to maintain your HP. If you lose in both Round 4 and Round 5, sell your Goblin pieces and withdraw all your pieces on board to steal defeat compensation from lose streak until Round 12. You need to accumulate 50 Gold as soon as possible either by a winning streak or a lose streak.
Mid-rounds: With 50 Gold at hand, you can Buy Exp with the Interest to reach Lv.8. During this period, try to get Siren and adjust your Formation, taking the pieces that can activate Feathered (6) Synergy effects as priority No.1.
Later Rounds: Upon reaching Lv.8, refresh the Store for the needed pieces, and try to activate Feathered (6) and Hunter (3) Synergy effects as quickly as you can, and meanwhile ranking up your pieces on the Chessboard.