User blog comment:EXDarkLight The Ephemeral/Tower Event Rankings/@comment-26039274-20180406002225

As someone said below, well-put teams comprising of only LRs and GURs can survive extreme.

GLRs are just to help for fast killing. Fast GLR team can make around 14 fights (including at least 4 rune boss battles) in the 30-minute rune time.