Okay, based on that and his character sheet it looks like he has space for some stuff.
Devil's Ego for a +4 profane bonus to charisma
Righteous Aura for a +4 sacred bonus to charisma
Divine Presence for a +5 sacred bonus to intimidate people who don't worship our deity (presumably Viserys himself) increasing to +10 against people who have one alignment in opposition to the caster, and +15 for those with two.
Improvisation for a floating luck pool. We have luck bonuses already, but they seem to mostly be one offs. This spell would provide a pool of 2 luck points/CL which can be spent to provide a bonus equal to the points used on attack rolls , skill checks, and ability checks. You can't spend more than half your CL in points on any one check, but that's still a hell of a bump if it's needed.
Other useful effects:
Crown of Glory - for 1 minute/CL it grants you a 10 ft/CL aura of celestial authority. Anyone with less than 8 levels/HD must stop what they're doing and face you. Your words are treated like suggestion spells and a telepathic communication effect ensures they understand you even if you don't share a language with them. Note that it is an evocation spell with a good subtype and not an illusion or enchantment spell with a mind effecting one, so it arguably shouldn't be blocked by most standard mental defenses.
Adoration of the Frightful - this ones just for laughs. It lets you translate fear statuses into friendly attitudes for the duration of the spell, which is hilarious but probably not appropriate for the public audience. Might be useful for the follow up meetings though.
overall, that's another +4 to all Viserys' social checks, followed by a pair of luck bonuses somewhere north of +10 with CL buffs.
Which means that if Viserys wants to intimidate a CE asshole who doesn't worship him as a god then he could slap something north of +27 on top of his existing intimidate check.
[X] Azel