I mean he's pretty menacing on his own. He kills innocent people, he rips Cyborg in half...
I think there's some hyperbole about Steppenwolf's quality as a villain. He's not the greatest villain ever, but he's serviceable. He definitely needed a bit more backstory/fleshing out, but hes not a completely shallow character either. Hinds did a very nice job of voicing him.
He's a bit inaccessible though. There needed to be a scene where he has a dialogue with someone from the league, or someone in his ranks...we needed to see a hint vulnerability from him before the end of the film.
The desperate to get home thing is fairly unique. Hes not conquering Earth for the sake of it
hes atoning for past failures, which the film delves into in grand fashion with the flashback, and hes doggedly determined to do so. The way he's sort of religiously into the Mother Box technology is also kind of interesting, if a bit over the top. Not sure if I buy the "Heggra" rumors about why he's talking to the box. Especially since Heggra is his sister in the mythology, not his mother.
I can't believe there are complaints about his formidability. He's an absolute badass in pretty much every sequence he's involved in. Clearly highly skiled and incredibly powerful.
I would have liked to have seen some more interaction between him and the parademons throughout the film, but they were mostly just cannon fodder. I do think the lone aggressor thing was the point. He was on his own, as hed essentially been exhiled. By the end of the movie, he might as well be begging to come home. Hes essentially a rogue terrorist cell of a larger group trying to make good.
Thats why the forces of Apokolips show up via a Boom Tube and operate in secret instead of bringing in giant warships. This is Steppenwolf and his forces, not Apokolips itself invading. The attack on Earth was clearly a last ditch effort on Steppenwolfs part. You can see his building fantaticism and desperation as the movie progresses.
I thought it was interesting that they chose to use Unity, instead of "Anti-Life" or some other force. "Unity", in the DC animated Universe is a hive-mind with tentacles. And lo and behold, the final sequence involved something very much resembling tentacles (I like to think it's a reference to Starro, myself, but it probably wasn't).
Visually, he looks ok. Best CGI ever? No. Terrible CGI? No. Hes clearly not human, so when he speaks, his face doesnt move like a humans does. Its less pliable, sort of craggy and rocky. I thought he meshed ok with his surroundings and interacted well with the other Leaguers.
They were sort of sowing the seeds for Darkseids methods. Its pretty clear that WB is waiting to see what Marvel does with Thanos before moving forward with Darkseid, which is the safe play, though part of me wishes they'd just gone ahead and used Darkseid.
Still, Darkseid, if we ever see him, will be a lot more than just an invader of Earth when he shows up. His threat will likely be cosmic, involve the Green Lantern Corps, New Gods, etc.
I do think that once you get into Apokolips, Darkseid, etc, you have to devote a decent amount of time to those story elements. That gets problematic. You cannot drop Apokolips/Darkseid/New Genesis as a concept into a story and then not develop it. Which is probably why this was originally conceived as two films. So using a character that requires less investment, like Steppenwolf, and containing the "history" to his story was probably the smart move.