The rules for Chaos Gifts in the Warhammer Armies Chaos supplement form a very good basis for the mutation of Chaos Champions. Any mutation gained during a battle can be kept from game to game, but a model who already has a mutation adds + 1 to his Eye of God roll for each mutation he already has.

Players who wish to retain Chaos mutations in this way might like to model on the extra claws, fangs, spikes and the other deformities visited upon their Champions by the fickle Gods of Chaos.

Eternal Labour

A character taken by his Chaos God to perform some eternal labour must miss D6 games. He can then be returned to your army with one extra veteran bonus for each game missed. This represents the experience gained by your warrior while in the service of his god. slaying unthinkable creatures and performing heroic tasks at his master's bidding.

Cosmic Duel

Models removed to undertake a cosmic duel are automatically returned to the army and can continue to fight in future games.

Spawn

Any Spawn that survive a battle can be incorporated into your army. All the Spawn's Chaos Gifts are retained from game to game. The player must convert a model to represent the Spawn in order to field it.

Spawn cost no points and can be deployed with your army at the start of the game. Its first move is always 2D6" straight forward, after which the Spawn continues to move randomly as normal.

Spawn remain with your army until they are killed. If the Spawn started life as a character or elite trooper it retains any bonuses earned up to that point, but earns no new ones.

If the Spawn is killed then it cannot be used again, although the model can be used to represent a splendid new Spawn rather than employing a counter.