PSA: The Diablo on Floor 98 of Item Tower counts as a kill for the SSM Fallen Sun EX Milestones.

I found this out when the "Kill 5" Milestone randomly popped up as completed.

Not an earth-shattering find, but an interesting unintended bug. My guess is they just used the same coded battle, swapped some elements, numbers, and replaced Waginu with Killia.