In 2e, the trick with call lightning would have worked. Items like rings of spell storing had fixed casting times.
In this huge arena, the 120 ft range of True Seeing is nothing. You can see a distance of 24 squares away on a map that's 120 x 100. Also, there's no (apparent) z cap, so a spellcaster could launch spells from 1000 ft into the air.
Plus, I think it's really hard to make an effective split level fighter wizard guy. Besides taking a level or two of the opposite class, I think the best way to use the class combo is to focus on good buffing spells for a very self contained character.
I think I've made a pretty decent fighter mage using the Spellsword class. The character is level 15, and 35 point buy, so he matches up well - in theory - against GoD characters.
Sir Tiberius human male
Pal 1, Fighter 2, Sorcerer 4, Spellsword 8. IIRC, all the stat boosts when to strength.
STR 18 (22)
DEX 13
CON 15
INT 12
WIS 8
CHA 16 (18)
Spd: 20 (40)
Ini: +1
Att: +11/+6/+1 (brilliant energy bastard sword +20/+15/+10 - with tatoos up +23/+18/+13) (bow +16/+11/+6)
Dmg: 1d10+8 17-20/*2 bastard sword, 1d8+5 +1d6 fire bow
HP: 116
AC: 27 (+1 dex +9 armor +5 shield +2 deflection)
F +12 (+22)
R +3 (+16)
W +10 (+17)
Power Attack, Exotic Weapon, Focus, Imp Crit: Bastard Sword, cleave, lightning reflexes, Leadership, Extra spell (3), Dragon's Toughness
Knowledge Arcana 6 +7
Religion 4 +5
Concentration 11 +13
Spot 16 +15
Listen 16 +15
Diplomacy 4 +8
Spellcraft 3 +4
Craft: Caligraphy 4 +5
Ride 4
Handle Animal 4
Arcane Failure 5%
Spellsword Cache
Channel Spell II
Divine Grace
Detect Evil
Immune to Disease
Caster level 8 - as sorcerer
Spells: 0: Detect Magic, Prestidigitation, ?
1: True Strike, Flamebolt (from R&R, similar to MM or lesser orb of fire), Shield, Expeditious Retreat, Jump
2: Craft magic Tatoo (FRCS), Cat's Grace, Assassin's Senses (R&R, increases threat range and multiplier by 1 for a short while)
3: Haste, Fly, Displacement
4: Flameshield
Cloak of Resistance +4
Mithral Full Plate +1 of Moderate Fort
Mithral Lg. Shield +3
Amulet of Spendor +2 CHA
Adamantine (+2) +1 Brilliant Energy bastard sword
Scabbard of Keen Edges
Boots of Striding and Springing
+1 Surestriking dagger
ring of sustenance
ring of protection +2
goggles of darkvision and see invis
Belt of Giant Strength +4
+1 flaming mighty (+4) composite long bow
40 masterwork arrows
10 +2 arrows
25 +1 arrows
Some potions
His cohort was a cleric.
I was actually considering using a very similar character, with some tweaks made to optimize for a one shot deathmatch. Some cheap tricks like Dust of Disappearence, etc, some Dispel protection, a bunch of useful scrolls, some skill points in Tumble along with items to boost tumble and concentration. While not exactly a melee killing machine, I think he's pretty strong all around.
I course, I judged Zalilad to be a potential killing machine - perhaps a fighter/weapon master with Ki crit for a 16-20 threat range with a scythe, along with goodies like Rhino hide, so I could be very wrong about the spellsword's effectiveness.