I don’t understand the ending and everything tbh, can someone explain?

so, taejun remembered everything else since entering the black room was a trigger. he understood the reason behind why everything started, which was all to do with their reflections in the black mirror which would send out a load of hands and attack the ones they wanted to. taejun came to terms with it because he realised he had done it once before without feeling any remorse afterwards, and went alongside yeonwoo. now they're just chilling around and doing what they want ig

Oh okay, thx for the explanation