The rules of the binding process that bound both the Prince and the assassin were wretched but not too unfair.
Emeros knew he could not command the assassin to his death. For the King's own attributes would never accept it. It was a fair treatment, an eye for an eye. It would not punish the offenders beyond the offended crime. The law of balance, the rule of the world, ensures things would go beyond the weight of the crime.
And in the laws that forbade Emeros was the fact that the offender had not desired to kill Emeros. And so, the rules stated that Emeros should have commands and orders that would endanger him or put him to death.
And so, Emeros plotted a way for him to fight, relay all the information, and die without ordering him to die but ordering him to prepare to wound Alistair.
The assassin used its powers linked to a Dark Dependent Ritual of releasing stored energy within the body to self-heal. Valler was quickly recovering from his wounds.