Shishio Gen's Last Battle Kekkaishi : Season 1 Episode 37

The fight continues with Yoshimori, Tokine and Shishio fending off a hot headed Gagin. The only chance for relief is for Shishio to transform into his full form, breaking the taboo once again. Though the Kokuboro army is forced to retreat, the Karasumori gang gets delivered a devastating blow.