Today, however, we now have an edition of D&D which actually has a sturdy system, balanced numbers, and a pre-existing mechanic that can bring this old mechanic back to life in a way that is both functional and entertaining. In fact, they have already implemented this as an optional rule...
Removing a Nikke from a slot will keep the slot closed for 4 hours before it can be reused, not that long considering the often multiple-day-long penalties in other games with a similar apprenticeship mechanic. Your first Synchro Device goal is to get 5 max limit break SR Nikkes and get...