Moonwarmer is an alternative unused version of the Watercooler, which is essentially the same thing as the actual battle.
Attacks

Moon Rain: Large moons spawn above the Bullet Board and fall down at a random angle.
A "special" variable can be adjusted to make the moons bigger and fall slower, taking up more space. This would presumably have happened every other turn, since it's the same variable that manages the spin of the Watercooler's droplets.

The Moon Rain attack without the special variable.
The Moon Rain attack without the special variable.
The Moon Rain attack with the special parameter.
The Moon Rain attack with the special parameter.

Strategy

Being a modified Watercooler, the ACTs work the same as in that battle but with different flavor text. (ActWarmer is the equivalent of ActCool.)
Quotes

Moon [First turn, double chance on other turns]
The rest of the quotes are generated from the pattern: {N,M,M}{o,oo,a,o,oo}{n,m,mo,n,m}:
Non
Nom
Nomo (half chance)
Noon
Noom
Noomo (half chance)
Nan (half chance)
Nam (half chance)
Namo (quarter chance)
Mon (double chance)
Mom (double chance)
Momo
Moom (double chance)
Moomo
Man
Mam
Mamo (half chance)

Flavor Text

You CHECKed the moonwarmer... The warms was confirmed to be moon. [Check]
A strong aura emanates from the Moonwarmer. [Encounter]
The moonwarmer shows no mercy. [Neutral]
The moonwarmer doesn't do anything in particular. [Neutral]
The moonwarmer leaves a hot silence. [Neutral]
The moonwarmer warms moons, warmly. [Neutral]
Smells like the faucet. [Neutral]
The moonwarmer's bubbles rest on the surface. [Tired]
The moonwarmer looks like it needs a refill. [Low HP]
[BegForMercy]
You begged for mercy... ... but the moonwarmer showed none.
You thought of some better, different ACTs to try next, instead.
[First repeat]
You begged for mercy... ... but the moonwarmer showed none.
This is probably because your NAME isn't YELLOW.
You begged for mercy... This doesn't do anything. [Second repeat]
Everyone chatted around the watercooler. [ActWarmer]
You told the moonwarmer it should actually be called a moonwarmest...? [Flirt]
You took a slow sip of warms and asked if it ever mooned...?
You asked the moonwarmer,"hotter"they doing later...?[sic]
The water turns pink for a second.
Susie puts cups on Ralsei! [S-Action]
Susie face-crushes a cup!!
Susie puts cups on Kris's eyes!
Ralsei labels everyone's cups!! [R-Action]
Ralsei cleans Susie's spill!!
Ralsei absorbs trace calcium!
The moonwarmer's water blushes a cranberry pink. [Spare conditions met]