This is one way you can heroic scale your SF, as well as any melee or ranged build in heroics. I've used sorc and arti and Favored Soul as example 10/10 splits.
Sorc Fist
DB 1-10S, 11-20SF
Max + Lvls Cha, other stats based on what you want to do with extra feats/AP. Can go WWA, or THF, or divine healing (heal skill). I skill heal on paladin levels to max/spellcraft/concentration/some umd (cha maxes it out), balance, and spot. When you swap to paladin level up your heal, spellcraft, and perform I guess.
Feats
1 Maximize
3 Empower
AP
Racial AP Dragons breath/caster levels
11 AP Air Savant +3 caster levels
11 AP FI Color Spray
23 AP Falconry helpless damage
Nice Optional AP: Divine healing 8 more AP / More Dragonborn stuffs (DC/spell power/wings) / bit more spellcrit/maximize reduction / 25 % HP Falconry 9 more AP
Lvl 1, would AoE 1 shot mobs in lvl 1 reaper dungeons, but went into lvl 2 (4 on reaper mode) instead, so almost 1 shot mobs with DB from racial AP.
Can do Bringing the Light for first savant bubble, then go into reaper Kobolds New Ringleader for rest of lvl to 2.
Lvl 2+ DB AoE 1 shots mobs in lvl 2 (4 on reaper mode) dungeons
Lvl 4+ So does meta scorch on at-level reaper, hitting mobs fully meta for 3x max health (put 6 ap in fire savant +2 CL to use scorch well)
Lvl 6+ so does fireball/Lightning bolt on at-lvl reaper (put 11 ap in fire savant when you want to use fireball for +3 max CL)
Lvl 8+ So does Shout on at-lvl reaper, still hitting mobs in reaper mode for 3x max health (sonic means you no longer need AP in fire savant as off element)
Lvl 10+ So does Ball lightning on at-lvl reaper
At level 15 GH mobs have 400-700 hp ... lack of spell progression and caster levels means *only* non-crit hitting mobs in reaper mode for 2x max health:
Sacred fist AC bonus is only when centered, but a staff is a centering weapon, so your AC spikes, saves spikes due to divine grace, and evasion rounds out defenses, with divine healing/LoH rounding out healing.
The 17-18 gear including sentient staff will let you AoE 1 shot most Sharn mobs in low reaper. A few tougher mobs and reapers will live through it. Basically after you stop taking sorc levels your damage will drop from triple mob max hp non-crit in reaper mode down to around mob max hp non-crit in reaper mode by Sharn at 18. Doesn't quite non-crit 1 shot the tougher giant sized mobs in reaper mode, but it does edit the pack down to SF scaling levels so you can finish with melee:
The following classes win splits when 10/10 with sorc for past lives:
Barbarian, Bard, Cleric, Fighter, Paladin, Ranger, Rogue
So this lets you edit dungeons down to size for 5 out of 6 of the melee/ranged classes, and scales your SF through heroic reaper Sharn.