Reception to Oscar Isaac's Apocalypse was mixed, some like me loved it, others hated it, others hated it from the get go. Those who loved it loved it because of how regal it was, how Isaac actually managed to make the character worth watching and how seductive his character was. Those who hated it either had legitimate complaints or didn't like that he wasn't a CGI character like Josh Brolin's Thanos. Here's the thing though, Thanos, Darkseid and Apocalypse - they're all the same character.
Yeah, DC has one Darkseid but Marvel has two. Nothing wrong with that, especially since even though both characters are inherently the same, they have both diverged and provided different storylines that each entertain in their own way. The thing is, if you didn't like Oscar Isaac's Apocalypse because you think he looked like Ivan Ooze (damn you guys really had to dig deep to find that though), this article isn't for you, get the [frick] out of here. For you other reasonable users, here's the article.
Oscar Isaac's Apocalypse:
The only thing I didn't like about Isaac's Apocalypse was that he wasn't physical enough, that we didn't see him personally decimate all of the X-Men. However, I liked why that was - he was extremely regal and had no need to do any of that when he could have his minions do it for him. His minions were all under his persuasion, and any inconsistencies there let's just blame on Kinberg. Isaac started of his performance powerfully and ended it as such as well.
When En Sabah Nur woke up, he was regal and walked with stature. You can see when he touches the car, though, he is confused why it isn't him that's decorated everywhere. When the Egyptians attack Storm, you can see he's confused why she's running from them instead of subjugating them. You can see the only time he's proud, is when he sees Magneto in the television. One of the biggest nuances you see in his performance though, is how he goes from regal and confused, to arrogant to frustrated.
As soon as Nur gets the Horsemen together, he's arrogant. Things are going his way, there is no way he can lose but then the X-Men take Charles Xavier away from him and he loses it. One of my favorite lines was when he's raving around the ruins of Cairo demanding Charles come face him or see the death of his "weaklings". The regal man who walked slowly in the beginning of the film is gone, now it's the angry God. Quicksilver tries to attack him, but Apocalypse makes the speedster is bitch, then he does the same to Mystique and then he does the same to every other X-Men as well.
It takes them all attacking him at once - on two different planes of existence - for him to finally be defeated.
How it will affect Brolin's Thanos:
What we've seen of Brolin's Thanos has not been impressive. He somehow looked his best in
The Avengers, looked weak in
Guardians of the Galaxy after Ronin got the Infinity Stone and his cameo in
The Avengers: Age of Ultron made that film look even more like a stepping stone. Except we're all excited, because an actor of such high caliber is playing one of the Marvel Universe's most powerful villains, a God-Like adversary who has a powerful weapon and how will he even be defeated? That last sentence could describe people's thoughts when it was announced Oscar Isaac was playing Apocalypse as well. The difference is that we've already seen Josh Brolin's Thanos and even though it hasn't been that impressive, we still haven't seen enough to say that it sucked. It hopefully is going to rock. It hopefully is going to be amazing.
Know this, if you loved Isaac's Apocalypse - you will love Brolin's Thanos. Why? Brolin's Thanos may wind up being more physical than Isaac's Apocalypse, but overall, they will likely play the character the same. Well, Brolin will only half play Thanos, the other half will be played by the CGI team. There's the difference between going for motion capture and makeup, Isaac's performance of Apocalypse was all him - Brolin's performance will only partially be him. That aside though, what makes anyone think that Brolin's Thanos will be any different than Isaac's Apocalypse?
They both play Gods who work with Celestial technology, are the strongest beings in the universe and when enhanced, can only be defeated when gangbanged by every other superhero. It's almost impossible for actual actors to play these characters because when they're in the states we love them most (as in when they are Gods) they have no real depth other than their simplistic motivations (Apocalypse wanting to kill all humans, Thanos wanting to kill all... everything) and varying powers (Apocalypse being every mutant and Mr. Fantastic in one, Thanos being well... everything in one).
It is especially hard for actors to get any depth from these characters, that Isaac managed to do so just goes to show how incredible an actor he is and trust me, it will be harder for Brolin to do so because like I've said, his performance isn't all his. Half of his performance will done by the CGI team. That's what people forget about motion capture, the actor compromises his performance and it could either end up great (Koba and Caesar, or Gollum) if the actor is in sync with with the CGI team or terrible at no fault of the actors (Beowulf would have been great it were, you know... a video game). I trust the Russos and think they're great filmmakers, but they aren't James Cameron and I don't know if they can make a Thanos as good as the N'avi, especially since Gunn couldn't do it.
I'm confident that Thanos will end up great, but don't assume that just because it's Marvel Studios Thanos will be amazing. There's a lot more at play, especially when considering Thanos as a character, has a lot less depth than most of the villains whose performances seemed half-assed in Marvel movies.
Conclusion:
Be excited for Thanos, but be cautious. Just because he looks like Thanos, doesn't mean you'll enjoy him as much as you think you will. Remember, Thanos isn't a complicated character but that's exactly what makes adapting him so complicated. The same problems faced by Apocalypse, at least critically, will likely be faced by Thanos unless the Russos manage to somehow make their third Marvel film a hole in one. Let's hope they do.