Is there a way to build this so that at lvl 18 this character can swing his weapon and cast a arcane spell and a divine spell.
At lvl 1 the magus can cast and swing as if two weapon fighting.
At lvl 10 the Mystic Theurge can cast a divine spell and Arcane spell of the same casting time at the same time.
Thus It holds that a magus mystic theurge could cast two spells one divine one arcane and still swing his weapon.
The only way you could do that all in one round is that the divine spell needs to be Quickened.
Why? the magus does not have to quicken his spell in any way.
Spell Synthesis (Su): At 10th level, a mystic theurge can cast two spells, one from each of his spellcasting classes, using one action.
The test does not even say it is a full round action just one action.
Granted This character can only do spell synthesis once per day. so he/she could only pull of this combination once per day.
Granted the character would suffer the full penalties the -2 to attack and spell from the Magus and the - 2 to both spells from the Theurge.
Still it is a mind numbing combination
Is there a way to build this so that at lvl 18 this character can swing his weapon and cast a arcane spell and a divine spell.
At lvl 1 the magus can cast and swing as if two weapon fighting.
At lvl 10 the Mystic Theurge can cast a divine spell and Arcane spell of the same casting time at the same time.
Thus It holds that a magus mystic theurge could cast two spells one divine one arcane and still swing his weapon.
In the current game I'm playing in I've decided to go magus / cleric mystic theurge. Spell combat only works with magus spells so you'll need to wait till you get magus 6 to qualify for broad study which allows for spellcombat/spellstrike with your other casting class.
As an magus oracle you'll need to go at least magus 6 oracle 4 MT 10 meaning level 20 you could cast two spells one round. If you went cleric instead it would be 19 you could use spell synthesis to cast two spells full attack and still have a swift action in reserve for a quicken or a magus ability.
Also note that your oracle curse /mysteries would never progress so you'd want to choose that one carefully, and that at magus 7 you could wear medium armor and cast arcane magus spells.
Great NPC crap PC.
Magus level 6 Oracle level 4 Mystic Theurge 10 to get to that trick. Not great levels 7-10 and level 11-19 not much better. Great seat 6th pc at the table but not 1-5. BaB +12 for melee type... Spells Oracle Caster level 14 and 7th level spell, Magus Caster level 16th and 6th level spell. 7 magus special ability, 7 Oracle special ability, 6 Mystic Theurge special ability. Your curse never get better. A lot of levels of suck to get to the trick. 19 levels... Cool trick not worth the wait. Huge MAD INT, CHA, STR, CON, DEX, the only on you can dump is WIS and need CHA 17 and INT 15 I guess that can go with a Scimitar and spend 3 feat Weapon Finesse, Agile Maneuvers, Dervish Dance to help with MAD. But that eat 3 feat and unless your human is all of your level 1-5 feats. 19 level of suck to pull off a trick that I cold do noly once per day at level 20 or higher.
Agian "Great NPC" the or the "World biggest Crap PC".
Still it is a mind numbing combination
Yes it's numbing in all of the general suckiness you take in both classes just to get one trick of dubious value that you can take once per day.
Given how much you nerf your magus and oracle to do this one trick... It's not worth it.
Still it is a mind numbing long wait to get a trick that do only once per day.