Step 1. Use one of your starters so as to get two monsters on the field
Step 2. Link Summon Knightmare Pheonix or Knightmare Cerberus using the two starters(note: If you used Formud Skipper, you can skip this step)
Step 3. Link Summon Knightmare Mermaid using the Knightmare that was summoned
Step 4. Using Knightmare Mermaid's effect, discard 1 card to special summon Orcust Knightmare
Step 5. Link Summon Galatea, The Orcust Automaton using Orcust Knightmare and Knightmare Mermaid
Step 6. Using Orcust Knightmare’s effect, Send Orcust Harp Horror to graveyard
Step 7. Using its own effect, banish Harp Horror to Special Summon Cymbal Skeleton from your deck
Step 8. Link Summon Longirsu, The Orcust Orchestrator Using Galatea, The Orcust Automaton and Orcust Cymbal Skeleton
Step 9. Banish Cymbal Skeleton in graveyard to special summon Galatea again from grave
Step 10. Activate Galatea's effect, Shuffling Cymbal Skeleton into the deck and adding an Orcust Spell or Trap card to your hand (Usually Crescendo or Babel)
Step 11. Using Dingirsu, The Orcust of Evening Star’s summon effect, XYZ summon it with Galatea
Step 12. Using Dingirsu, The Orcust of Evening Star's other effect, Attach your banished Harp Horror to Dingirsu