The "combo" posted below ISN'T much of a combo, but it's something that I have managed to pull off a couple of times during play testing. It does EXACTLY 8000 damage and it can be done as early as Turn 2. No graveyard setup required.
Herald of Perfection (ATK position)
The Agent of Creation - Venus
Daigusto Phoenix (in the Extra Deck)
MYSTICAL SHINE BALL(s)!
1) Ritual Summon Herald of Perfection in ATK position, or simply shift an existing one into ATK position. (For the latter, it is advisable to do the shifting JUST before your Battle Phase. Just in case.)
2) Summon Venus to spawn 3 Mystical Shine Balls, with at LEAST 1 in ATK position.
3) Xyz Summon for Daigusto Phoenix and activate its effect!
4) Remove Venus (on-field) to Sp. Summon Master Hyperion.
5) Nuke your opponent’s Monster by removing the in-grave Shine Ball.
6) Swing for game! (500 + 1500 + 1500 + 1800 + 2700 = 8000).