Slenderman: "Commence with the sacrifices!"

Eyeless Jack, Capricorn, Zero, Clockwork, & Libra sacrifice Gemini & Sagittarius to appease Zalgo.

Sally Williams, Aries, Puppeteer, Kagekao, & Bloody Painter sacrifice Virgo & Cancer for the return of Leo from Zalgo.

Dr. Smiley, Jeff The Killer, Taurus, Pisces, & Ticci-Toby trade/sacrifices Aquarius' soul to Zalgo for Scorpios' soul.