Phainon is a 5-star Physical Destruction character in Honkai: Star Rail who needs specific teammates to synergise with his abilities. Effective team compositions can include characters like Sunday or Bronya, who act as batteries by consistently buffing Phainon, allowing him to frequently use his Ultimate. Robin can also be included to advance the team's actions, ensuring Sunday and Bronya can quickly recharge Phainon's Ultimate.

Example teams include Phainon, Sunday, Bronya, and Robin, which can clear endgame content but may suffer from skill point issues unless Bronya is at E1 or has her signature Light Cone. Sparkle can replace Robin to help with skill point regeneration. Other harmony alternatives are Ruan Mei and Tribbie. Players can also pair Phainon with debuffers like Cipher or Jiaoqiu, who increase damage dealt against enemies, though these units do not help refill Phainon's Ultimate. A F2P-friendly team can be built with Tingyun, Bronya or Ruan Mei and Lynx. Lynx increases the chances of Phainon getting attacked, regenerating his ultimate while also healing and protecting the team."