>>536749275
Time for a history lesson. ACK is short for anti-crack-kun, an absolutely deranged poster with literal autism who takes offense at any pairing for works he follows that supposedly aren't explicitly backed/intended canonically. He also vehemently denies that "ACK" as an entity exists, and also that anyone who says otherwise, posts "non-canon" pairings he doesn't support, or disagrees with him in general, is actually his personal boogeyman !Akemi/Austin (an old tripfag) trying to troll him. He first showed up in Madoka threads around 2013, and notoriously made those threads completely unusable for an extremely long time, but later made appearances in a bunch of franchises/series that are at least vaguely yuri-adjacent like Gridman or Symphogear. You can still find him derailing threads in /a/, /gig/, /akg/ and /hsrg/ to this day. He has had some pretty legendary melties and he always gets banned but instantly ban evades. Picrel is one of them.
/a/ Ack melties: https://desuarchive.org/_/search/boards/a.desu.meta/text/Akemi/deleted/deleted/
/vg/ Ack melties https://arch.b4k.co/_/search/boards/vg.meta/text/%21akemi/deleted/deleted/

He is also a mindbroken loser who gets angry whenever someone makes fun of his typos or does a callback to an argument he lost. This is why certain words like 'solar beam', 'c6r6', and 'shaky' elicit a response from him. It just means he lost an argument pertaining those topics in the past.