Which Mechanical Boss is the Hardest?

[whoneedsnamestbh]

you've got it backwards, unless expert mode did some weird stuff to skeleboi.
But Skeletron Prime loses defence per every hand killed.

It's actually the other way around.
Edit: I'm stupid and the screenshots didn't work. But go on the terraria wiki, it shows that Skeletron in Expert gets more defense per hands killed, while Skeletorn in Normal and Skeletron Prime in any difficulty don't. You'll also see this yourself if you look at the damage numbers you get against expert Skeletron or Skeletron Prime.

 

[Dreadnautilus5000]

you've got it backwards, unless expert mode did some weird stuff to skeleboi.
But Skeletron Prime loses defence per every hand killed.

No, the only thing that happens to his defense is that it doubles when he's spinning.

 

[BuffIing]

you've got it backwards, unless expert mode did some weird stuff to skeleboi.
But Skeletron Prime loses defence per every hand killed.

This is wrong. I just killed skeletron prime with the Blade Staff two days ago and they did the exact same amount of damage to him with and without his arms. He has 24 defense at all times, except for when he's spinning where he has 48. There is no other change with skeletron prime.

Expert prehardmode Skeletron, on the other hand, starts with 60 defense, goes to 35 defense with one hand, and finally goes to 10 defense with no hands.

 

[whoneedsnamestbh]

Slightly off topic, but I’d actually argue that Queen Slime is harder than any single mech. There’s a ton of projectiles being thrown everywhere, which is especially dangerous in phase 2 when she drops them from above you. You also have to deal with her minions, which are overall a hell of a lot more abundant than Destroyer’s probes, and Crystal Slimes can be more dangerous if you have to track over them. Granted she’s still not super hard because you can avoid most of the attacks with a super long skybridge, but she’s still harder than the mechs except maybe the Twins.

 

[BuffIing]

Slightly off topic, but I’d actually argue that Queen Slime is harder than any single mech. There’s a ton of projectiles being thrown everywhere, which is especially dangerous in phase 2 when she drops them from above you. You also have to deal with her minions, which are overall a hell of a lot more abundant than Destroyer’s probes, and Crystal Slimes can be more dangerous if you have to track over them. Granted she’s still not super hard because you can avoid most of the attacks with a super long skybridge, but she’s still harder than the mechs except maybe the Twins.

She's absolutely more dangerous. The mechs are by far the easiest 3 hardmode bosses to begin with because of how dated their attacks are. I honestly would put Prime and Destroyer below Golem.

 

[Storm Diver]

Problem with the mechs is their AI has literally not been touched since they were first added back in 1.1, and even expert mode doesn't change them, apart from the prime head moving faster.

 

[tenthousandhoops]

"Cry, Terraria, cry for Prime's mercy! There will be n-" Skeletron Prime has been defeated!

Technically, The Destroyer's head gets a massive damage increase in Expert (70 to 280) but aside from that it's the same dumb worm. It's weird how some bosses radically change in Expert (Eye of Cthulhu, Duke Fishron) but others, like the Mechs are untouched. At least Master Mode was consistent.