Obviously in your opinion. For me it’s RoTF Leader Optimus. If you owned this figure you know why.

Edit: Goddammit I made a typo. Should be, “What transformer has the hardest transformation?”.

 

Out of figures I own, Apollyon.

Although I don't own it anymore, it was MPM6 because my copy was so defective it couldn't be transformed fully into vehicle mode

 

Of ones I own, T30 Dreadwing. Never actually transformed him because it frustrated me too much, oh, six years ago. I should try again, actually...

Fixed.

 

A lot of the earlier bay movie 07', DOTM, ROTF lines were hard going especially ROTF Prime which was a real chore. Some of the 2000' RID cars weren't exactly enjoyable either.

Masterpiece can be a pain but it is supposed to have a strong element of the Japanese Puzzle Box ethos in the designs; so the difficulty enshrined into these (outside QC faults) is purposefully part of the figure.

Lots of 3rd party figures also come into this. Some are just hard to transform worsened by poor QC and design. I find very few 3rd Party figures enjoyable but for me due to both the complicated sequence, fagility and poor QC, Apollyon has been the worst.

 

Revenge of the Fallen Mixmaster is definitely up there.

 

If we talking about ones i dont own mp36 but for the one i own tlk nitro zeus

 

this fucking thing was a nightmare for 7 year old me to transform, I'm pretty sure he's still hard figure to transform

 

Beast Hunters Smokescreen. Movie toys ain't got nothin' on that asshole.

 

I’ve never had trouble with figures like ROTF Mixmaster since I was a kid.

What I do find damn near impossible though, is transforming Generations Straxus without his tread bits falling off the balljoint. There is literally less then a mm of space and the treads just can’t get out of the way enough for the arm to rotate around.

 

Alternators Grimlock. I never managed to transform it back.

 

The original BW Barney Megs lol. I was about 7 or so a the time I think. I could never get it transformed properly because I was dumb and impatient I guess. I got frustrated and it sat in a basket in my room for years, all mangled and half transformed. Idk what happened to it, but I'm definitely kicking myself in the buns for not hanging on to it, or even relaizing how cool it was. Dx

Haven't really come across anything frustrating enough to make me give up on it since I've started collecting though. I'd say MP-36 is the biggest pain I guess, but that's only because mine is a KO and the leg transformation is super super stiff. The fragile paint doesn't make it very inviting to transform either.

 

Cybertron Prime from the first video game still gives me nightmares. Small and has many steps to transform. I remember a lot toys from Revenge of the fallen making my 5 year old neighbor very frustrated.

 

Lol, I put all my alternators and binaltech away in storage a few years ago. Transformed them all back into car mode for easy storage except for Wheeljack (same mold) and Grimlock. Those two are bubblewrapped in their bot modes.  

 

Alternators are a pain in the ass to transform. I like complicated transformations, but they had a lot of steps that inevitably ended in paint scuffing and such.

 

For me, it would be when I was wee lad of 9 years old, trying to transform BW Tripredicus and assemble him correctly. Every little piece had to be juuuuust right.

 

Also this. And Magnaboss was a bitch to transform when I was a younger, getting everything lined up was never easy.

 

Evasion mode Optimus was a bitch and his arm broke off.

 

Alien Attack Firage and Generations Sergeant Kup. Kup really shouldn't be hard but those damn springs in his chest infuriate me.

 

I will have to go with MP36. That thing no matter how many time I transform him. I still need to watch videos or look at the instructions. TE01 is close, but after changing him a couple of time I can change him pretty fast from memory.