Prior to Skybound
Nadakhan needed the Realm Crystal to free his crew so he went to Hiroshi's Labyrinth Stronghold. The Nindroid Sentries, led by their general, tried to protect it but were eventually destroyed by Nadakhan.
Prior to March of the Oni
As the Realm Crystal was moved to the Borg Tower vaults, the Nindroid Sentries were presumably placed there as well.
- 56. "Public Enemy Number One"
- Public Enemy Number One (credits)