I just had a thought: earthsoul genasi Aegis of Assault swordmage with 16 Strength (18 for genasi), 10 Dexterity, 11 Constitution, 16 Intelligence (18 genasi), 8 Wisdom, and 13 Charisma. You take the Soldier of the Faith multiclass feat and enter the Champion of Order paragon path solely for the Certain Justice level 11 encounter attack power.
Every fight, you start off by marking the biggest and meanest monster (preferably a melee enemy to make the most of daze) with your Aegis of Assault and then whacking it with Certain Justice. If the attack misses (it shouldn't, really, given its additional +4 attack bonus), you engage that enemy normally. If the attack hits, you move away from the enemy since it can't take immediate or opportunity actions, and proceed to engage a different opponent with your 1/encounter Divine Challenge mark, leaving the original big bad enemy in the dust dazed and weakened. There isn't much of a way for it to shake off the mark, unless it somehow happens to have the Ignoble Escape level 6 rogue encounter utility, so it's going to stay dazed, weakened, and marked until the end of the encounter thanks to you.
If you're up against a solo, you might want to ask for Aid Another actions from the rest of the party just so that you can be absolutely sure that Certain Justice hits.