#slime pit

It's interesting, that early on the very Horde Symbol was supposed to be a parasite that attached and controlled people, kinda akin to DC's Starro:

This unused idea, seems to have inspired over 30 years latter the idea of Horde Prime's chips controlling others:

While mechanical, the chips appear to also posses biological or biomechanical elements:

The idea of Horde brainwashing, was re-used to a degree with Adora, and Kevin (though both were under influence of Shadow Weaver's magic, rather than "just" Horde specific technology, magic or entities) in the Filmation series (and Adora in many other continuities).

The Slime Pit is also possibly inspired by this:

The Slime Pit did appear in the Filmation She-Ra series, but it weakened it's victims rather than brainwashing them.

Curiously, SPOP also has an equivalent to this, with the green liquid bath that Horde Prime also used for brainwashing purposes. Ironically, it's first victim (and one of the two we see along with Catra), is Hordak himself:

Curiously, and gruesomely, this green liquid appears to be the same as the blood of Horde Prime and his clones, and which Horde Prime absorbs from them (along with their life force), to maintain his bodies longer (making this all seem pretty vampiric).

Because Catra and Adora end up being arguably more angsty combined than the canon show grudgingly fighting on the same side eventually, we need some comic relief and foe-yay.

Entrapta never ends up with the Horde because Adora uses Princess Prom entirely for espionage. Entrapta would also end up working kind of like Q in James Bond to Adora;

But that still leaves a possible Entrapta and Hordak still end up in a dynamic.

It starts when Entrapta leaves helpful notes for possible improvements on wrecked Horde machinery. 

Entrapta doesn’t get a lab buddy, she gets a rival! Like in those history books Etheria’s past researchers! (Academia is contentious after all.)

Entrapta basically makes Hordak an unwilling pen pal, sending him notes on how he can improve the robot designs her own robot soldiers wreck.

Hordak does not know how to deal with a pretty girl praising his attempts to destroy her and everything she loves.

The insolence does get him to oversee war efforts more, and also ironically leads to him developing a better working relationship with Shadow Weaver (they still hate each other, they're just more professional about it and he stops air-drowning her)

Hordak combine's his cloning knowledge with Shadow Weaver's sorcery to create a biological engine of destruction that spreads the mind control slime she invents.

Pictured here with the removable organ accessories

Because the Slime Pit used to be the Horde’s and I’m taking it back