Here's my MP/SP Firestorm build -- "We Have Ignition". I use the identical build to farm levels 13-17 in SP as well as farm MP in the infrequent event that I play MP. It's simply Firestorm and armor, that's it. It's intended that I can mostly ignore whatever the opponent does, whether in SP *or* MP. Xavier Level 20 Dwarf Wizard Staff Of The InfernoStaff Of Glowing CoalsBrin's Storm LocketMagma ScepterChartwell's AmuletBanik's Bubbling BaubleForceful RobesIberial's BootsPerfect ToughnessFocused Pyromancy1 x Improved Telekinesis1 x Telekinesis3 x Firestarter3 x Ember Burst2 x Burning Fingers2 x Shimmering Aura2 x Combustible2 x Stone Spikes7 x Firestorm1 x Resistant Hide2 x Volcano2 x Toughness1 x Force Cone1 x Fire Spray1 x Forgetfulness1 x Rusty Armor1 x Force Bolt1 x Short Perplexing Ray1 x Dangerous Maneuver1 x Simple Bash Yzerman Level 20 Dwarf Wizard Staff Of The InfernoWym's LavastaffPenteth's OrbBooming RingMagma ScepterBrin's Storm LocketFirehide RobesGlimmer BootsPerfect ToughnessFocused Pyromancy3 x Firestarter2 x Ember Burst1 x Burning Fingers2 x Combustible1 x Hardy Mail12 x Firestorm1 x Reflexive Teleport3 x Path Of Knives3 x Volcano2 x Toughness1 x Run1 x Forgetfulness1 x Rusty Armor1 x Force Bolt1 x Squeamish1 x Resistant Hide Zap Level 20 Dwarf Wizard Staff Of Glowing CoalsStaff Of The InfernoBanik's Bubbling BaubleMagma ScepterBooming RingYaro's ScepterForceful RobesBertha's Big ClogsPerfect ToughnessFocused Pyromancy1 x Improved Telekinesis1 x Rusty Armor1 x Telekinesis1 x Walk3 x Ember Burst1 x Officer's Harness2 x Burning Fingers2 x Combustible1 x Force Cone6 x Firestorm1 x Resistant Hide2 x Path Of Knives2 x Volcano2 x Toughness1 x Fire Spray1 x Reliable Mail2 x Force Bolt1 x Short Perplexing Ray3 x Firestarter1 x Penetrating Zap1 x Simple Bash Note that there are two gold tokens left over on each wizard for MP, and one of them has a blue that could be upgraded to a gold if desired. As it is, I just spam Firestorm regardless of whether or not it's actually beneficial. Playing like that, the build will likely float in the 1100-1200 range. The goal is fast games, period. I couldn't care less what the rating is. If you wanted to make it more competitive you could replace all of the Staff of Inferno for almost anything that isn't Combustible, such as the Walnut Staff, Trembling Staff, any of the cold staves... tons of options if you're so inclined.
Trembling staff have combustible too. Staff of inferno isn't good because it have combustible and it makes you lose alot of games as you said
The ideal no-token replacement for Staff of Inferno would likely be one of the Legendaries -- Mullik's Blisterstaff or Xemu's Staff. But you could still do worse than a couple of low-level commons -- Turquoise Staff or Staff of Defense.