Talk:Underworld Tower to Heaven/@comment-81.171.71.142-20170809221018/@comment-16682378-20170809230813

It's random & VC's rng is pretty streaky at times: I've had 25+ encounters without Rune bosses appearing (almost gave up), yesterday I had Rune bosses almost nonstop.

The green 'rune' isn't an accual rune, instead it refills 1 BP & does not add to the rune time bonus.