The series earned Hallum some of the best reviews of his career, as he and his creative team received praise from feminist critics for showing the realities of motherhood.

[7] In 2007, using the pen name " Dennis Hopeless", he created GearHead (with penciller Kevin Mellon), a four-issue comic about a female auto mechanic searching for her lost brother.

[8] His next notable work didn't hit shelves until 2011 when Hallum reunited with artist Kevin Mellon to create LoveSTRUCK, a supernatural graphic novel inspired in part by Frank Herbert's Dune and Garth Ennis's Preacher that was published by Image Comics.

[12] While some publications were hesitant to embrace the Season One concept, Hallum's novel garnered generally positive reviews,[13][14] with Comic Book Resources calling it, "easy to understand, fun to read and still pretty wide in scope.

"[15] Hallum's next work for Marvel was 2013's Avengers Arena, an 18-issue comic series in which the villain Arcade kidnaps 16 teenage superheroes and forces them to fight each other to the death.

Critics praised the relatable, fun storytelling of the comic with IGN calling it, "laid back at times and outlandish at others" while scoring it an 8.6 out of 10.

[27] In late 2016, Hallum wrote the main story in a one-shot licensed comic called "WWE: Then, Now, Forever", which was published by Boom!

[28] The comic became an ongoing series simply called WWE the following year with Hallum continuing to write the main story and Daniel Acuña replacing Mora on pencils.

After the end of Jean Grey in early 2018,[35] Hallum continued writing for Marvel, including a digital Cloak and Dagger comic miniseries to coincide with the premier of the Freeform television series adaptation of the characters.

io9 commented that "Dark Visions’ view of the nurse's desires takes established feminine power fantasies and treats them as delusional jokes, right up until the moment it leaves its female protagonist a crumbled heap on the floor.