Entreating An Entity
All entities can be considered malevolent, benevolent or neutral. Of course, their attitude depends on whether a character is good or evil himself (Dormammu might seem quite benevolent to his worshippers, while everyone else would see him as a malevolent daemon). But no matter whether the entity is chaotic or not, he can usually be entreated by a magician of any belief and will answer. This subject has been covered in the use of Dimensional Energy in the Arcanum of Magic but it should be reiterated that entities do not take the time to peruse every single entreaty. They sow their favors like seeds, and hope that they take root in soil of their liking. If an entreaty is stated for a specific purpose that is obviously opposed to the entity's desires, he will usually just ignore it, though he may choose, at other times, to punish the entreating party for offending him.
Many times in the past Doctor Strange has called on an entity whom he does not fully understand to help him in an enchantment, only to later find that entity is opposed to everything he believes in (he once even called on the energies residing in the Darkhold). Usually he never contacts them again, at least not as a regular source of spell. Once recognized as an enemy, it is very unwise to contact an entity again.
Some entreaties are actually methods for focusing the desire or purpose of a mage. By calling upon his dead master or his personal belief in a god to help him, a sorcerer reminds himself of what he stands for and what he must do to stop an opponent. Usually, though, entities are extradimensional existences.