Which coding do I need to copy to make Malenia Second phase activate on different Map?

[indigo mesa]

So, I'm trying to make Boss vs Boss battle. I'm using Malenia. Her first phase is working great. But I want to know how can i activate second phase when the first phase die on the ground. Also, How can I hide the first phase? I know everything is in the darkscript. But which lines do I need to copy or change?

[glossy thorn]

the events for malenia are 15002800, 15002810, 15002811 and 15002820

15002811 should be her phase 2