Clearing Blackhole is like eating broccoli. You don't do it because you like it or want the rewards, you only do it because it's there. And then you complain how bad it is.
Introduction
Wide Area Search Enigma Black Hole, a.k.a. Blackhole, a.k.a. BH, a.k.a. butthole, is a gamemode introduced to the player upon completing chapter 4 of the main story.
This gamemode is a series of infinitely retryable stages with no key costs, single battle, no functions. As this gamemode diverges heavily from standard play and has bloated enemy stats, many stages will require specialized strategies with clever use of units, micro, or builds.
This post mainly serves as a summary of various strategies, unit comps, and unit stats used to clear the most challenging of these stages. Ping polyethylenimine#2914 on discord for stage suggestions, strategies, or errors.