[3] In September that year, guitarist Scott Ian confirmed that Bello and drummer Charlie Benante were "coming over to start writing for the next record" and subsequently posted images on Twitter of the band working on new material.

[4] By the end of October, the band had arranged seven new songs, with Ian describing the direction of the new music as "aggressive, fast, even riff-ier than the last record".

[5] By February 2014, the band had a total of 12 songs written, though were continuing to write so that they would have more material to choose from for inclusion on the final album.

'Cause I wrote "Lone Justice" way back when, on the Spreading The Disease record, which was based on that character, and I decided to re-visit it, because, metaphorically, there's so many things you could use it for[...]I'm kind of weaving in and out of reality and fantasy in that song.

"[16] According to Benante, "Evil Twin" was inspired by events like the 2015 attack on the offices and staff of the French satirical publication Charlie Hebdo and various other mass shootings.

Ian added that it was about by the actions of people "who feel they have become judge, jury and executioner over their fellow man", calling this mindset the "evil twin" of humanity.

Praise was given for its consistency and focus,[27][30] as well as the contributions of newest member, lead guitarist Jon Donais,[30][33] and many critics cited the 8-minute "Blood Eagle Wings" as a standout.

[25][33] Dom Lawson, writing for The Guardian gave the album a 4/5 star rating, describing it as being "full of the anthemic choruses and hulking riffs that have always driven their sound".

"[27] J.C. Maçek III of PopMatters was also positive, giving the album a rating of 7/10 and stating that For All Kings "stands out as powerful thrash metal with a distinctive sound that is unmistakably Anthrax."

[30] Chad Bowar of Loudwire, like Lawson, observes that the album "delivers the thrash that they are known for, but also sees them explore other sonic pathways without losing touch with their core sound", and also praises vocalist Joey Belladonna for sounding "even better and completely at ease" compared to Worship Music, in which he performed songs not originally written for him.

The 2016 Limited Edition Box Set of the album includes a cover of "Carry On Wayward Son", which is close to the original of progressive rock band Kansas from 1976.