Custom Boss's Change Background

Hello Minnaze(Everyone) I Newbie here I have asking about the Boss's change background, Last time I watched the video of Tenkarider's fought Titan EX made by Mr. Edrin his custom boss hack back ground are change I'm surprise it change it so I want to do my own Super Boss and Special Boss ala Kaiser Dragon and Omega Weapon with the style of Mr. Edrin's change background and how they used the code that the creatures background change.So if anyone of yours can advice or help I'll be appreciate but if Not its OK too and please anyone of you before you say nonsense post read first I only to post this is because I thought this site is trusted and helpful members and staff members, I hope my problem are solved.....

Note: Sorry guys If I mistrusted person I hope your understand....