That Yellow Triangle Guy - The Owl House X Gravity Falls

Elixir Trouble

Eda was scrounging through a chest, King and Luz to her side. She had just finished a game of Hexes Hold'em, and her curse was flaring up. I know those two things aren't really correlated, but it's what happened in the episode so I'm bringing it up for viewer convenience. 

"Oh no." She kept looking through the chest, but all she could find is empty bottles. "This is terrible. I'm all out of elixir!"

"Uh-oh. Last time that happened, you turned into this thing." Luz held up her phone and showed Eda a photo of herself as the Owl Beast.

Eda looks at the photo for a little. "I know I should be repulsed, but that look is fierce." 

"Eda!" Luz exclaims!

"You're right, you're right," Eda says, mildly understanding the severity of the situation, "We need to head to the market."

"Market!" Luz stands and turns around, preparing to leave, but she turns back, curious about something. "Wait, Eda?"

"Hm?" Eda asked, not really paying attention.

Luz hesitated for a moment before asking "Why haven't you just... made a deal with Bill? To get an infinite supply of elixirs? Or to stop the cure entirely?"

"You kidding?" Eda said, nonchalantly. "That equilateral freak would say I 'owed him a favor'. He could show up at anytime and ask me to do anything. I'm not risking that."

Luz looked at Eda with pure terror evident in her eyes. "W-WHAT?! WHY DID YOU MAKE ME DO IT?!"

Eda looked at Luz, noticing the fear on her face. "Uh, or not. I'm not a demon expert or anything. You don't need to worry about it." Luz started hyperventilating.

"Relax. What reason would he even have to hang around the Owl House other than to spectate?"

Luz slowly started to calm down, seemingly eased by these words. "You're right. Thanks, King..." She said, calm yet anxiety still evident in her tone.

King tugged on Luz's shirt. "Uh, I didn't say that." King proceeded to point towards an area behind Luz.

Luz was confused. "What, then who...?" She turned around to see... that yellow triangle guy, in the flesh. Or whatever material he's made out of.

Bill was leaning in mid-air, his cane somehow keeping him steady against the literal nothing he was leaning on. "Yello?" He said, glowing yellow as he uttered his greeting.

Luz yelped and fell back onto the ground in shock. "Wh-what are... how did you...?"

"Yeah, it's a pleasure to see you again too, Light Bulb." Bill said, sarcastically.

Luz just stood there, stuttering incoherently, not even able to make a response.

"What, are you gonna take all century? Sheesh." Bill rolled his eye.

Luz kept sitting in a whirlwind of uncertainty and confusion before she settled on a response. "Why are you... here?"

"Why? Simple!" Bill spun his cane around. "You owe me a favor! A favor that could be anything!" He laughed maniacally before staring at Luz dead in her eyes.

"ANYTHING..."

Luz gulped involuntarily. "Oh, um, well, I don't... I mean, you're... a triangle, so I can't really..."

"What?" Bill looked at Luz confused.

"Wait, what are you talking about??" Luz looked at Bill even more confused.