Fafnir support Fusion and sacrifice guide + Destroying The Reaper | Persona 5 Royal

Step 1: Just fuse Maria
Step 2: Get Genbu from the Compendium
Step 3: Use Maria and Genbu to fuse a Loa and Pass done the Ave Maria Trait
Step 4: Grab Hope Diamond from the compendium
Step 5: Use the Loa and Hope Diamond to fuse Fafnir, Pass Down Ave Maria, Auto-Matarukaja, Auto-Marakukaja, and Auto-Masukukaja.

With Fusion done, now its time for the sacrificing to get the other skills.

Step 6: Get Lilith from the compendium
Step 7: Get Bishamonten from compendium
Step 8: Trigger a Fusion alarm by killing shadows until the alarm triggers
Step 9: Save your game, then sacrifice Lilith to Fafnir for Makarakarn, if you dont get Makarakarn then reload and try again.
Step 10: Trigger another fusion alarm
Step 11: Repeat step 9 for Bishamonten
Step 12: Get Thermopylae onto Fafnir to finish the build, Either through skill card or sacrifice

And there you have it, the finished product.

Then we destroy The Reaper.