Sparkles the Wizard is DeathSpanks trusted sidekick and friend. If you play co-op the main player will control DeathSpank and the second player will control Sparkles. The person controling Sparkles will not be able to get achievements but they can help the main player to get theirs.
He can do his own attacks which vary from DeathSpank's hacking and slashing. He is a mostly strategic character, having to manage his spells from a distance so that the duo do not get defeated. Because he has no armor, Sparkles is quite vulnerable, so that DeathSpank has to work together with him to do much effect.
Magic Missile-Sparkles fires a strong bullet of magic. This is his primary attack, usable from any distance against any foe, including the undead. In the beginning of the game, in the first area where Ghosts are seen, Sparkles can destroy them easily, making to the Golden Treasure Chest faster. Fast recharge time.
Fire Breath-Sparkles shoots fire out of his mouth, blowing back and slightly damaging any foe in his path. When he is spun in circles rapidly using the analog stick, it has almost the method of an Orb of Invulnerability. It is not a damage dealer. Be aware that this fire can also push back DeathSpank, so be sure he is inside the 'Defense Field' created by the fire. No recharge time.
Clone-Sparkles summons a clone of himself, which sometimes summons it's own clone, depending on the number of enemies around. The clones run up to nearby enemies and explode, dealing massive damage to anything nearby. Slow recharge time.
Heal-Speaks for itself, really. Sparkles heals both him and DeathSpank at the push of a button. This is indispensible for boss battles, really. Medium recharge time.