I agree with Marcel Sarot in that this is the best way to characterize the passibilist position:
“(1) God’s feelings, or the quality of His inner life, can be influenced by the world, but only in a personal way, and not in a causal way. This means that God always remains Master of His own emotional life, that He never can be victim to an emotion. His emotions are always controlled by His will, which also means that they can never run counter to His perfect judgment, which always takes all relevant information into account. (2) God is immutable with respect to His moral character and His abilities. This means that God’s moral character sets limits within which God can have feelings and emotions: God can never have malevolent or unjust emotions. He is also immutable with respect to His abilities, which means that He can never be incapacitated by His feelings or emotions: His suffering can never detract from His omnipotence. (3) God can never be overwhelmed by suffering or by other negative emotions. The resources of happiness available to God are inexhaustible, which makes Him the happiest being in existence. His suffering is embedded in His happiness, not the other way around” (Sarot, God, Passibility and Corporeality, 67).