In the campaign I’m running right now I have a big bad that is pulling the strings of the evil in the world. Demi god like power so I’m allowing 30 class levels and Mythic 10.
The 3 characters I want it to be a hybrid of are Lord Zedd from Power Rangers, Hordac from Masters of the universe and Shao Kahn from Mortal Kombat.
I’m thinking a bonded object wizard (or magus) 20 (all of Zedd’s powers from the staff), soul drinker 10. Maybe draining soul monk. Think it boils down to what I want from each inspiration so:
Zedd-Staff dependency for casting; however phenomenal magic power when used
Kahn-Able to drain souls and use them. (Soul drinker); excellent hand to hand fighter
Hordac-psychic vampire template with partial cybernetic body. A mixed of martial proness, technology and necromancy
Ok, let's assume your players will be at a high enough level (and mythic rank) soon enough to fight this thing.
And it sounds to me like you really want to build this creature level by level, instead of taking roughly reference values (AC, HP, saves etc.) and some CR-appropriate powers and calling it a day.
The bonded object flaw will only work if Spellcraft is low enough. A DC of 20 + spell level means a maximum of 29 (assuming you stop at spell level 9), hence 30 Spellcraft ranks will let him succeed automatically, even before adding Int. So I'd give him only a few ranks, with a certain spell failure chance (like 25%) in mind. And I'd try to make sure that disarming / sundering / otherwise neutralizing the item is difficult but possible, and that the players have a chance to know about this weakness.
Martial chacters as bosses tend to have the drawback of very short battles. One side closes, both sides trade full-attacks and it's over after one, two rounds. Not very epic, eh? You can stretch the battle by adding miss chances, difficult terrain, minions, escape abilities (like the Dimensional Agility line) and debuffs. And, let's be honest, by simply improving HP by 100%, 200% or more.
Be ready to get back to the drawing board once you notice the PCs are way, way stronger than expected, with their high-level abilities and mythic powers.
Mythic tis a silly place. On second thought, let's not go there...
Sythesist Summoner (with a construct/inevitable theme for the techno stuff)/Monk with a Legendary Item Staff with Intelligence and lots of spellcasting (Staff of the Magi as a base)
you can fight in hand-to-hand, summon the souls of the defeated to fight for you (just reskin some Summon Monster) and the staff itself will have a ton of spellcasting options and boosters for you.
11 levels of Soulthief Vitalist can satisfy the Psychic/Psionics and about half of the Soul-draining feel, especially with Ranged AoE Hostile Empathic Transfer.
What about Soulthief Vitalist 11 and Soul Drinker 9?
Maybe throw 1 level of Monk in there, and get Blind-fight + Intuitive Fighting, and now you have your +Att and AC tied to your Wisdom score, and Vitalists are SAD with Wisdom, so this is excellent synergy.