@capricieux Adding on to what the other person said, by acknowledging Father's existence and sins is to acknowledge that Heaven was in the wrong (failed to stop him and/or outsmarted by a human). So Amaterasu and Yato made a deal that if Yato does not solve and prove Heaven's shortcomings, Amaterasu will silence Yato for his treason (which is suggesting that they are flawed) against Heaven.
It was previously mentioned that Takemikazuchi was considered one of the 'rebel' group (those who participated in the covenant)... I wonder if Amaterasu will decide to kill them in order to truly 'cleanse' Heaven? Might be a good place to also bring back side characters like Kiun who is practically a foil to Yukine and Kazuma- I feel there is more to tell for his character.