Bug Fables - Defeating Mr. Tester in the Test Room

Mr. Tester is an enemy that appears only in the Test Room of Bug Fables, and wasn't intended to be defeated (it has 500 HP, 5 defence, and heals itself to full each time it takes an action). Here I demonstrate a way to beat it (with legitimate endgame stats; the test room does provide ways to arbitrarily increase attack etc, but I have not used any of those options). Recorded for Part 78 of my Let's Play (hosted on Something Awful and LP Beach) of Bug Fables: the Everlasting Sapling (played on Hard Mode).
The strategy I'm using here is a variant of the "needle flash" or "rainbow needles" build, stacking Sleepy Needles, Electric Needles, and Status Booster on Vi to maximise the chance of disabling the enemy (because we cannot beat Mr. Tester unless we prevent it from ever taking a turn once we start doing damage).
There is a glitch where waking an enemy up from sleep by damaging it will still cause it to miss its next turn, so triggering either sleep or Numb once per turn is all we need to do. Of course, from there we're still fighting through the status resistance mechanic (Mr. Tester may start with 0% resistance to each of Sleep and Numb, but each time it's inflicted that increases by 13% and 15% respectively), and are on a time limit to beat it before it becomes immune.
Fly Drop is used to deal damage after successfully inflicting status, instead of continuing to spam needles, so as not to waste resistance unnecessarily. (I tried straight Needle Pincer spam first, and could not make that work because it would become immune too early).
Medals:
5x TP Plus
2x Power Exchange (Vi)
2x Last Attack (Vi)
2x Poison Attacker (Vi)
Weak Stomach (Vi)
Eternal Venom (Vi)
2x TP Core
TP Saver (Vi)
Status Booster (Vi)
Strong Start (Leif)
Hard Charge (Vi)
Poison Needles
Sleepy Needles
Electric Needles
Empower+
A.D.B.P. Enhancer
Spy Specs
Total MP used is 76, so the remaining 3 levels' worth were converted to TP. Strong Start and Spy Specs are superfluous, and removing them could enable an additional level of TP to be taken. Vi has 8 maximum HP (enabling Hard Charge with TP Saver to turn on Last Attack).
There are some possible improvements available to this strategy that I thought of afterward. For instance, during the setup, having Leif also spam a Break variant would bring Frigid Coffin into play as an emergency option for when the needles fail; I found Frigid Coffin doesn't freeze if it deals zero damage. Also, using Ice Cream instead of Drowsy Cake to set up Weak Stomach and Hustle Berries would've let Vi set up Hard Charge beforehand, and have less exhaustion on her first attacking turn. That said, I preferred to show this attempt as it was the first successful one I recorded.
Full context in the threads:
forums.somethi...
lpbeach.co.uk/...