Event characters, or collaboration characters, are characters who did not originally come from Sdorica, but instead from other games which Sdorica has had collaboration event with. So far, there's been two crossover events.
Event characters are often limited-time and are only available to obtain during the course of corresponding collaboration event. DEEMO Characters can be obtained throught Origin Infuse and Contract Crafting.
Sdorica X DEEMO Characters
This event was first available from November 7th to December 5th in 2018, and a rerun was held from November 13 to December 13 in 2019.
Alice could be unlocked for free by completing the event stages, collecting Music Sheets and obtaining her character minerals from the Event rewards tab. Deemo and Masked Girl were available through a limited-time Melody Infuse.
Sdorica X Cytus II Characters
This event was available from January 22nd to March 3rd in 2020.
Ivy could be unlocked for free by completing the event stages, collecting Dilapidated Archives and obtaining her character minerals from the Event rewards tab. Nora, Neko and PAFF could be obtained through the limited Variation Infuse.