Where can I watch The Strongest Sage With the Weakest Crest?

The world's number one assassin has been reincarnated as the eldest son of a family of aristocrat assassins. In exchange for being reincarnated in another world, a goddess has imposed upon him one condition. "Kill the Hero who is prophesied to destroy the world." This was to be the mission in his new life. The synergistic effect of the vast knowledge and experience he gained that made all manner of assassinations possible in the modern world, and the secret techniques and magic of the fantasy world's most powerful family of assassins turn him into the greatest assassin of all time.

22 years ago, Tokyo was destroyed by a cataclysmic earthquake. This area became known as the Lost Ground and it gave rise to Alter Users, people with unique psychic abilities to change matter and create Alters with incredible power. To bring order back to the Lost Ground, the special police force HOLO was formed and using Alter Users created HOLY to capture and control the renegade Native Alters. One such renegade is Kazuma. The power of this Alter, Shell Bullet is put to the test when HOLY comes knocking on his door and Kazuma must fight for his freedom and the safety of his friends.