Step 1. Special Summon Photon Thrasher using its effect
Step 2. Special Summon Photon Vanisher using its effect
Step 3. Activate Photon Vanisher's effect, adding Galaxy Eyes Photon Dragon to your hand
Step 4. XYZ Summon Starliege Photon Blast Dragon using Vanisher and Thrasher
Step 5. Using Starliege's effect, Special Summon Photon Advancer from your hand (or normal summon it if Infinite Impermanence was used)
Step 6. Link Summon Union Carrier using Starliege and Advancer
Step 7. Activate Union Carrier's effect, equipping Photon Orbital from the deck to Union Carrier
Step 8. Activate Photon Orbital's effect, sending itself to the graveyard and adding Galaxy Soldier to the hand
Step 9. Activate Galaxy Soldier's effect, discarding Galaxy Eyes to special summon itself
Step 10. Activate Galaxy Soldier's effect on the field, adding Galaxy Knight to the hand
Step 11. Activate Galaxy Knight's effect, special summoning Galaxy Eyes from the graveyard
Step 12. XYZ Summon Number 90: Galaxy Eyes Photon Lord