Based on the following bounty https://civitai.com/bounties/1074/millenniummon-digimon-please
This was a tough one, because of all the extra appendages, and its not great, but it still sort of works.
I found the best prompts to use are ; Millenniummon2024, Digimon, 4 arms, claws, two shoulder cannons, yellow phoenix,1 horn
If you figure out a better way to prompt this, let me know in the comments.
Weight should be as close to 1 as possible, but you can experiment with lower results.