He's surely one of the best actors out there right now.

Not to make you feel old but these movies are over 10 years old.

Is he though? Sure, he's great in his roles, but his mannerisms and personality pretty much stay the same regardless of the role. Someone like Gary Oldman, or Ed Norton are far better actors IMO. They disappear into their roles.

I think these two particular roles had a lot of mannerism overlap. That, and it was the same director in a similarly genred historical fiction revenge thriller. In Alita: Battle Angel and Downsizing, he's playing different roles. Its just a shame the material doesn't hold up to his talent for the roles.

But I'll also note that Gary Oldman, in particular, really goes ham with the physical transformation. From slick terrorist in Air Force One to manic ex-con in Harry Potter to... Jesus Christ look at all those facial prostheses in Darkest Hour, its not just the acting but the degree to which he's willing to physically change himself to fit the part.

Matthew McConaughey and Christian Bale pull this as well, to really intense effect.
- Christian Bale is definitely committed to his transformations. A lot of times I still see him in his roles, but he thoroughly sold me on his method acting ability in The Big Short. Holy shit, man! That was like watching a completely different person on the screen.
- Yeah Christian Bale in the Machinist is something else.
Both his most famous roles have a similar way of speaking because the roles are pretty much the same. The efficient and precise German. The genre is also the same. I've seen a german comedy of his where he is completely different.
- What's that one called? I'd like to see it.
I think it's more his expressions, like the tiny details that make you feel like he's really the person he's playing on the screen. Regardless of makeup or physical change, this is noticeable in how Tarantino told him to hold back during rehearsals to really bring out his costars' reactions in the final take of various scenes. That has nothing to do with what the character is or what he's wearing or his physical condition.
I didn't even know Gary Oldman was both Sirius Black and Commissioner Gordon until like 5 years after those movies came out.
How many movies have you seen him in to make a fair comparison?

His best known roles are very similar, true, but there's more to being a great actor than just having a lot of range.
- Only 3 so far. Basterds, the Django one, and Alita. I feel like I've probably seen him elsewhere in smaller roles, but I can't name one, so I'll stick with three.

Also, his character in Django Unchained was an inversion of the Magic Negro trope: a very white character who exists solely to develop the main character.

In the second and third acts, yes, but he does have his own thing going on in the first act. He's absolutely an inversion of that trope, but he's also much more fleshed out than some of the characters he's an inversion of.

Which really speaks to how lazy a lot of those writers were when it came time to flesh out their non-white characters.
That's a pretty big stretch for his Django character.

His archetype, you will find, is just called a "mentor"
That's a new term for me. Thanks for deepening my appreciation of the film.

he really is. when I see him in a movie i know it's going to be a ride.

I don't recommend ailta battle angel....but he is the best part of it
- Alita is awesome

Christoph Waltz kills any role he's in, and the weirder and creepier the better.

There's a Prime series called The Consultant it's so creepy, weird, yet fantastic, and Waltz plays the titular character and when he shows up in the series he cranks the weird up to 11.

He always plays the creepy weird guy though. I don't think that makes him a great actor, I think that makes him a shoe-in for the roles he's cast to play. He pretty much just plays himself.
- There are always distinct character differences, like the two referenced in this post, also by no means does he only play weird characters, the guy has a 30 year acting career, however he may be getting typecast for the more bizarre roles these days, or maybe he's like Nick Cage, where he's more attracted to the weird roles these days, either way, I always enjoy the roles Waltz plays.

Criminally underutilized as Blofeld, not once, but twice.

For me, he's probably #2 on the "can't pull eyes away from screen" list after Daniel Day Lewis (which is basically cheating).

Daniel Day Lewis can do some compelling drama roles, but he's one of those method actors who lives as the character until the film is complete. It can make for some powerful films, but sometimes it turns out like Jared Leto's Joker. Or Christian Bale's freakout on set, where he said he was deep in character and some set guy walked through and interrupted the scene.
- Oh, I'm sure he'd be miserable to live with and be around. Probably insufferably pretentious. But he's so good tho.