It's totally reasonable, as the bloodlines in that trait are mechanically more or less the same as the ones ordinarily available. Eldritch Scion doesn't really do DD very well though, since it doesn't progress most of your magus stuff, and losing levels of spells hurts more. For what you seem to be going for I'd go Paladin 2/Sorcerer 3/DD, some people prefer Barbarian over Paladin as well. At high levels this does really well at being an almost-full caster and then switching to an almost-full melee monster at the drop of a hat.
Seems like Brutal Pugilist Barbarian is what you're after. http://www.d20pfsrd.com/classes/core-classes/barbarian/archetypes/paizo---b arbarian-archetypes/brutal-pugilist It's a Barbarian that gets some help with grappling. You're probably using Animal Fury and Beast Totem for natural attacks (and pounce!) Alternatively, a Brawler is even better at grappling, and at high levels his unarmed strike damage dice are just silly. No rage though. I think Mutagenic Mauler could be fun for this, depending on how you feel about the alchemical flavor.
You're definitely going to need Boon Companion. If you want more than 4 levels of a sneaky class, you could take Inquisitor (Sanctified Slayer) with the Animal Domain, but there's not much multiclass synergy there. If you're just trying to stack up as many sneak attack dice as possible, take a level of Brawler (Snakebite Striker), a level of Unchained Rogue, and a level of Inner Sea Pirate. This will cost you some BAB though.
Dragon companions probably fall under Leadership, which would probably be possible in this case since it sounds like your GM is already into the idea. Dragonne ( http://www.d20pfsrd.com/bestiary/monster-listings/magical-beasts/dragonne ) is the most established dragon-like, rideable option but a wyvern would probably be considered reasonable. If you can't make Leadership happen, but do have the mount from a class, you can take Monstrous Mount to get a griffon. Griffons are not very dragon-like, but they fly and have claws if that's what you're looking for.
Pick two:
Alternatively, going for four levels of Fighter can get you Greater Vital Strike. Not sure it's really worth it, compared to the opportunity to breathe fire/cast Irresistible Dance/be really huge |