The extremist Rafidah Shia claims that fasting on Ashura was initiated by the Umayyad Nasibi to celebrate on that day. Responding to this unfounded claim is simple:

The narrations on the merits of fasting on Ashura are found with authentic chains in both Shia and Sunni hadith collections. This Sunnah was narrated by over a dozen Sahabah, confirming its authenticity.
Fasting is haram on Eid days, a well-known fact for every Muslim, except for the Rafidah it seems. If Sunnis wanted to celebrate on Ashura, they would indulge in munching, beating drums, and playing trumpets like the Rafidah.

The simple truth is that Iblis has inspired the Rawafid to abandon the beautiful Sunnah of fasting on Ashura and replace it with indulgent practices, including eating, drinking sweet juices, giving out sweets, beating drums, engaging in absurd cosplay, and participating in excessive self-beating pagan mourning rituals.

To any rational observer, their so-called ‘Azadari’ (mourning) appears more like a grotesque carnival than a genuine expression of grief. The Nawasib (Nasibis) would undoubtedly take pleasure in witnessing such carnivalistic shenanigans, deceitfully presented as a way to honour and remember Imam Husayn. In reality, it is a distressing mockery and parody of the tragedy, perpetuated by those responsible for the killing of Husayn ibn Ali (may Allah be pleased with him).