For some context, when one scratches a bit the back-story of this guy, some interesting facts pop up:
Momika came from Qaraqosh, a town in the Al-Hamdaniya district in the northern Iraqi province of Nineveh[5]. He was an ethnic Assyrian and raised as a Syriac Catholic.[6][7] During the Iraqi civil war, when Christians became persecuted by the Islamic State of Iraq (the precursor of ISIS), Momika joined the Assyrian Patriotic Party and worked as a security guard for the party's headquarters in Mosul. According to Iraqi government sources, Momika fled his hometown in 2012 after the local court found him guilty of causing a wrongful death during a car accident and sentenced him to three years of imprisonment in Badush.[8][9]
After the fall of Mosul to ISIS militants in June 2014, Momika joined the Popular Mobilization Forces (PMF) to fight against ISIS.[10] Specifically, he has appeared in videos in military uniform, as a part of the Christian unit "Spirit of God Jesus Son of Mary Battalion" (Kataib Rouh Allah Issa Ibn Miriam) brandishing firearms and pledging allegiance to the Imam Ali Brigades (to which the Christian unit is a part of), which are a PMF faction and part of the Islamic Movement of Iraq.[11] The Imam Ali Brigades are known to have close connections to Iran and is considered to be an Iranian proxy.[12] The brigades were also accused of committing war crimes and engaging in sectarian violence.[13] It's said that Momika was also affiliated with the Syriac Assembly Movement, a political party that received support from the Government of the Kurdistan Region.[14]
Momika also founded the Syriac Democratic Union and the Falcons of the Syriac Forces in 2014, an armed militia which was affiliated with the Christian militia Babylon Brigade, the armed wing of the Babylon Movement.[12] In 2017, Momika was involved in an internal power struggle with fellow Babylon Movement leader Rayan al-Kildani, which he lost. He fled the country as a result.[15]
In 2017, Momika fled to Germany with a Schengen visa, where he announced his atheism and apostasy from Christianity.
The rest of the article also describes multiple instances of him behaving erratically (e.g. threatening someone with a knife etc).
So before we go to the standard «western right wing troll» stereotyping, we must acknowledge that this is a veteran of the fight against ISIS who experienced persecution of his community during the Iraqi civil war and who probably was suffering from all sorts of trauma.
Does this excuse his behaviour, no. But it does explain it, way better than simplistic caricatures putting him in some «western racist» pigeonhole. He definitely did not deserve to die and he probably had some very legitimate reasons to hate Islam, a religion that he personally experienced in a really fucked up and extreme form in an extremely fucked up and extreme situation. Sadness all around.