28th June 2020, 1:58 AM
The level editor you're referring to is probably naxxol indeed, I think Firebird made it. It's still online
http://naxxol.github.io
video sequence with copy paste and reflect stuff
https://youtu.be/_NxoYbzrxVw?t=763
http://naxxol.github.io
video sequence with copy paste and reflect stuff
https://youtu.be/_NxoYbzrxVw?t=763