Primite provides a useful Rank 4 engine that lets you go into either Merrymaker+Sarger (for Regulus) or Dempsey (for Air Lifter). Also, Drillbeam is a crazy card.
The main line you are looking to do is:
- Have Hydrant, a body, and Lode on field (example: opening Beryl + Emergency)
- Link Hydrant into Clockwork Knight
- Send Lode to search Clockwork Night
- Link into Barricade -> pitch Night
- Banish Night -> Search Regulus
- End phase add back Lode
This is fairly easy to thread into the standard R-ACE link climbing with Preventer into Promethean.
Side deck cards are just flex Extra decks choices. E.g. Link Spider is nice for S:P, Controller is nice if you only open Beryl (make Sargas, link into Controller, summon Regulus), etc.