- Ꮒ- + Ꮥ- becomes ᏂᏗ-
☞ The Ꮒ- prefix can indicate “had already begun” or “had already occurred” when used with the past tense form.
You are indicating a past event happening alongside another past event. The events are “beside” or “next to” each other.
This requires a change of the ending to “-oi”.