In the upcoming episode titled "Sinner of Despair" of "D Gray Man Hallow," Allen will be seen trying his best to save Tokusa's life against all odds.
CLICK HERE to watch whether Allen saves Tokusa or not and the fate of Kanda and Alma.
In the previous episode titled "Little Goodbyes," Allen finally met Nea, the 14th Noah, in his sub-conscious state. However, soon afterwards, he started to have visions of Mana Walker and suddenly, Allen's cursed eye awakened that caused the Noah within him to disappear, much to Allen's disappointment.
Allen was able to see Alma's Akuma soul and to his surprise, found out that it was actually the woman whom Kanda loved in his previous life. Before Allen could have done anything, Alma self-destructed. However, he left his body behind.
Allen carried Kanda and a weakened Alma on his Noah's Ark to the secret underground chamber beneath Mater. Once there, Kanda embraced a dying, guilt-ridden Alma.
Majority of the Exorcists have already been destroyed while Lavi and Bookman disappeared and Chaoji getting critically injured. The moment Allen tried to save Tokusa's soul, Link appeared out of thin air and bounded Allen with a spell due to which, Allen was unable to move even for an inch.
The next episode will emphasize on Allen's efforts to save Tokusa and trying his best to defeat Link. Whether he will be able to do so or not, will be seen once the episode airs. Besides it, the fate of Kanda and Alma will also be revealed in the upcoming episode.