New runner here and I have watch a few runs as reference before doing actual timed runs. I heard deviljoe at AGDQ2015 mentioning there were setups being discovered (but still unreliable) for the boss battle pikeball glitch in wich you can get very quick kills. I have been searching for this glitch and explanation on how it works but all I've been able to find is Yaria Fu's run and the 2 quick kills achieved with the glitch. Still have no clue how it even works.

This Glitch is called a Quick-Kill and is possible for Squid baron, Hypno Baron and Nega-Shantae. It instantly start the script as if the boss is defeated.

¤You don't use PikeBall for a Quick-Kill, that is another glitch to dupe gems.

To get a Quick-Kill on Hypno Baron or Squid Baron you have to transform into any animal on the same frame you get hit. While you Dancing you still get dmg, because the invincibility-frames when you get hit, still counts down even if you dance. If you do it correctly, you will see that something is wrong with the boss. After you collected the seal, the game ports you out. (Only used in Any%no OOB, 100%)

Nega-Shantae is hard to get. You have to get hit on the same frame you hit her. So you whip your hair and hope that the hairwhip animation hits her the same frame your invincibility-frames goes of. ¤SideNote: You can't use Dancing because she steals all your powers. It sounds easy, but you lose about half a heart everytime you mess this up. (Trick can be used in every Category)

The Reason why this Glitch works is, because the game is very bad in handling 2 things at the same frame. When you start an animation and get hit at the same time or when you get hit on the same frame, the error-handler will kick in. At this moment the game don't know what to do and starts the script that will handle all things when the boss is defeated.

I was playing the game on a casual 100% run just now and accidentally got the quick-kill. It wasn't triggered how you normally would either. I can't explain what happened clearly, i wish i had recorded it. I had triple pike ball on, and was whipping nega-shantae and the quick kill triggered when she ran into me. No immunity frames or timing. In theory, I either hit her as she hit me (keeping in mind there were no immunity frames), or I hit her the same time as the pike ball did, or I whipped her + piked her + she hit me all at the same time. It was quite odd, especially since i was trying for the old fashioned kill.

It is exactly that. You can get it on the first hit. When you hit her on the same frame she hits you, you trigger the quick_kill. We use a setup with invincibility frames, because it has visual cues.