Understand the rules and power dynamics of the manga world. Know who the allies and enemies are. Also, keep an eye on hidden plot devices that could help or hinder you.
To survive as a villain in a BL manhwa, you have to be strategic. Understand the weaknesses of the heroes and exploit them. Also, build alliances when it suits you, but be ready to betray them if necessary.
Surviving in chapter 3 of the manhwa as a player requires a combination of things. First, know your character's strengths and weaknesses. Second, use the environment to your advantage. And third, don't act rashly; think before making any big moves.
One should stay low - key. Don't draw too much attention to yourself as an extra. Just do what your role requires and blend into the background. For example, if you're an extra at a party scene, just mingle a bit and don't interfere with the main characters' interactions.
One should first understand the rules of the omegaverse. Know the different roles and their characteristics. Stay out of the main characters' way most of the time. Blend in with the background and just observe. Also, make friends with other extras for support.