Ravaging flame: autotargeting, high range (even outside screen, and on different height levels too!) flame engulfing move, very similar to Diablo's one. Great fire based damage, plus subsequent burning damage, insane damage if charged(yes, it can be even charged! and while you do so you can change target/rotate GR).
Chain flechette: GR grabs his chain, and breaks it in front of him in multiple chain links, hurling them in a wide, short arc, causing fire damage and monstruous knockback damage with 100% on airborne opponents. It's kind of a shotgun move..
Fiendish chain: another great ranged attack, only Daredevil has one similar to it. GR extend his chain VERY far (if there's enemies around, even this one has autotarget) grab a enemy (it works also on little object) then it pulls him back towards GR, with good chain based damage. If charged, the extended chain remains in place while you keep pressing the button, immobilizing the target (although it doesn't work on bosses) and allowing the other guys of the party to beting the crap out of the unfortunate minion, before GR finishes him by pulling him back.. the charged pull is so powerful that sometimes i hurl the opponent very high and behind GR...
Chains of retribution: a radial attack with swirling chains and fire, if charged can popup enemies, good setup for chain flechette.
Fear: GR kind of screams moving the skull in disturbing ways, causing enemies around him damage and to run away from him terrorized, with lowered defences, great for crowd control.
Damnation: GR shoots a stream of hellfire from his right palm, every enemy struck by this catch fire and starts to run maniacally around, setting afire every other enemy he touches and slowly burning. If you keep pressed the button you can continue the firethrowing experience until you want/energy runs out, rotating in place GR.. great move for total hellfire CHAOS with storms of enemies in little spaces
Penance stare: i think this thing is the only dedicated boss killing move in the game. A short ranged, almost throw distance flash of GR eyes causing, for a time(50 seconds at least) every damage done by GR on the enemy to return as GR health... Awesome move as finisher, GR can this way fight bosses without fear....
Throw+ strong attack: i put also this because i consider it almost a special move... GR launch the enemy high in air then catches him with the chain and slam him down two or three meters in front of him, then again and again and again untile the enemy is dead. You can change direction of every slam, and GR moves also forward a bit each time. And naturally, you can slam the guy OVER other enemies, or breakable things.
Normally i use Ravaging Flame, Fiendish chain and penance stare, but in some stages (like hell, where fire/elemental resistant critters are more common) i use the Chain of retribution/chain flechette combo...
Also chain flechette is really good after an uppercut combo!