Solaire's potential kit, seems rather self-evident to be honest. His heavy iron armor and thick, non-anime build, make him a clear heavyweight, somewhere around 120~ in Smash 4 metrics, edging out Snake for the title of heaviest human. (I mean look at the guy. His outfit just looks heavy). He packs a medley of powerful defensive options, his sunlight shield could block projectiles and parry attacks, leading to a devastating counterattack, and his experience in rolling through attacks is second to none. Combine that with his access to a projectile, and he'd be the ultimate cancer.
Neutral Special Attack: Lightning Spear
Solaire's neutral special has him pull out a bolt of golden lightning and hurl it at his enemies. This attack can be charged up by up to two stages, first becoming the Great Lightning Spear, with piercing properties, then the instanteous Sunlight Spear. (The Sunlight spear is not actually instantaneous in Dark Souls, but it's also not something you have to charge up. I figured there should be some payoff for such a long-charge attack).
Custom Move 1: Lightning Stake
Instead of throwing the spear, Solaire slams it down, creating a large, powerful explosion. Basically it's Ike's Eruption.
Custom move 2: Lightning Ball
Solaire throws an orb of lightning into the sky, where it steadily moves forwards, firing off bolts of lightning every few seconds. The size and power of the attack is increased by charging. In Dark Souls, this was a miracle known as "Blinding Bolt", but given it's nonindicative name, I figured a more typical one might help.