Maybe Ulqi won't be sealed as long as Grimm thought he would be.
Just long enough that Ichi and Grimm will get healed.
I'd like to see the three of them fight against each other. It could help Ichigo fight them if they were to fight against each other also.
Or maybe Ulqi will break free before Ichigo and Grimm are finished fighting.
"For Feanor was made the mightiest in all parts of body and mind, in valour, in endurance, in beauty, in understanding, in skill, in strength and subtlety alike, of all the Children of Illuvatar, and a bright flame was in him"