I had a situation in a session where a Gelatinous Cube was trying to grab a player that specialized in damage shields (Dragon Magic Sorcerer). There were two situations where I wasn't clear on what should happen.
First there's an ability that's attached to the Sorcerer's daily called Lightning Breath. This ability creates a shield after the ability's damage which causes people that attack him to be pushed back one square. When a Cube grabs a target with such a shield do they both get pushed one square toward the Cube due to how engulf works, does the Cube get pushed away since he has to grab as part of the description of engulf, or does engulf just negate the push effect?
Another situation is while the grappler is sustaining the grab. The sorcerer has an ability that happens when using Burning Spray that gives him a damage shield for a round. The shield causes anyone who attacks him in melee to receive his strength mod in damage. Since the grappler is holding him, does he take that damage or does sustaining a grab not trigger that effect? Same with Engulf with Cubes, does the damage shield do damage to the Cube while the sorcerer is engulfed?