Forum:Gravity Bind/Ultimate Tyranno?

So, say my opponent plays Gravity Bind. After a while, I summon Ultimate Tyranno. Its effect states that when it enters the Battle Phase, it can and must attack all monsters on the opponents side of the field. Does Ultimate Tyranno's effect still work, despite Gravity Bind being on the field, or do I still have to get rid of Gravity Bind before Ultimate Tyranno can attack?