Sinfire, is a Feral (Savage Species) Diaboli (Dragon 327) okay?
If so, I'd like to ask to change the DIaboli from an Outsider to a Fey. Not for power reasons (imo Fey is weaker than Outsider), but just for flavour purposes - I'd like to reflavour the race as fey, who have sprung spontaneously from nature/green moonstone as defenders of the wild. Then I'd like to reflavour incarnum, no longer as souls, but as binding the raw power of nature to my command. With the Fey Diaboli following an Animist religion, but focused on Magical Beasts instead of animals, so you would appeal to the Purple Worm Totem in order to bind Wormtail Belt, etc
IF that's okay then I'm thinking start as a Feral Diaboli Totemist 2 // Shapeshift Druid 2, with feats as Barbed Stinger (Serpent Kingdoms), Multigrab (Savage Species) and Greensinger Initiate (ECS). Greensinger gives me some social skills and spells for some fun out of combat.
Then continue as Totemist 20 // Druid 20 the whole way (tempted to retrain to Wild Shape, in which case pick up Natural Spell and Share Soulmeld), and ending up with feats like this:
Flaws: Barbed Stinger, Multigrab
1: Greensinger Initiate
3: Shape Soulmeld (Mauling Gauntlets)
6: Bonus Essentia
9: Greater Multigrab*
12: Double Chakra Bind (Totem)
15: Planar Touchstone (for Incarnum Domain)
18: Expanded Soulmeld Capacity
* possibly move this to earlier in the build, but I will likely need magic items to get the Dex prereq
Customary Soulmelds being Girallon Arms and Muling Gauntlets for grappling purposes, Phase Cloak/Blink Shirt for mobility, and Sphinx Claws for pounce later on. Also picking up the Mask of the Tiger and some Serpent Armour for Track and Combat Reflexes (with large Wild Shape forms). Basically intended as a melee juggernaut and battlefield controller.
Personality wise, I quite like the base Diaboli description - in spite of his fearsome appearance, he actually has a heart of gold. Probably a vegan, who would ideally like to be a pacifist if only the world would let him (if I had the feats spare I might go Exalted with VoP), meticulously polite, a truly beautiful singing voice. Similar to Chumley in the Myth books.