I've been working on a concept recently that uses a level 4 heavens wizard. I don't have a catchy name for it yet, but basically, it's designed to get mileage out of the fact that harmonic convergence is the only offensive buff that can be cast in a 12" bubble that also benefits war machines. Re-rolling 1s to hit and wound begins to add up when you fire off two helblasters, two mortars, two cannons, a rocket battery... (ok, I don't actually use that much, because I'm testing at 2,000 points - but it only get better, the higher you go).
To make sure you get convergence off, you basically force the enemy to throw dispel dice stopping chain lightning and/or comet of cassandora and/or thunderbolt and/or iceshard blizzard. All of these excel at being high-priority dispel targets (nobody wants a comet to stall their advance when the artillery is raining down, or a thunderbolt on their small, elite unit, or a chain lightning ever).
Plus, once combat hits, you can just keep casting convergence and blizzard. It's not quite as good as some of the other buffs in the game for our low-stat empire troops (convergence becomes better the more accurate/strong/high armour your troops are) but between it and blizzard you can certainly swing combats your way, while the battery continues to fire at whatever it can.
I haven't had much of a chance to try it out yet so I can't say for sure whether I'm on to something, but the use I have had with it has been reasonably positive.
