Rate the villains
One of the things that I definitely enjoyed in Minecraft Story Mode is the interesting cast of villains that Jesse fights during his adventures.
Ivor: As a villain, I gotta give him a 5/10. It just felt rather clear from the beginning that he was suppose to be the bad guy who caused the problem and his motivation just felt rather weak and strange. I never really understood why he did what he did. But Ivor definitely works better as part of the main characters. You can laugh at his humorous villainous traits yet admire his newly restored heroic nature. So for that role I give him an 8,5/10.
Aiden: 8/10. I almost gave him a 6, but I felt that the final duel against him in Episode 5, felt satisfying. You can partly understand the jealousy that he feels and that has made him more jerky and dark. He was manipulative enough to temporally become the ruler of Sky City and if it wasn't because of land beneath the city, he would have killed Jesse and Isa. And as I mentioned the final duel felt awesome.
The Nether Storm: 7/10. A terrible force of nature. I love the design of the creature and it was a really threatening antagonist. But character-wise, there was not a lot of room for that. It was just rather generic and one dimensional with its goal.
The White Pumpkin: 9/10. This was the first villain who can match Jesse in pure fighting skills. The White Pumpkin use all tools and traps to its advantage and use them greatly to bring a great deal of trouble onto Jesse and his/her friends. A manipulative and cunning opponent as well as having Darth Vader vibe. The White Pumpkin was a pretty cool villain. (I know the identity, but for fun sake, I am keeping it a secret.)
PAMA: 10/10. The most creepiest and most dangerous adversary. PAMA being a machine made by Harper, he has essentially conquered his entire world, reduced it to a barren wasteland and commanding the whole world as his army. When he captured and forced you into his hive mind, he gains all of your knowledge. He nearly succeeded in building a world portal and thus was the greatest threat to the Minecraft Universe and it will be questionble if anyone could have been able to stop him.
Hadrian and Mevia: 9/10. Cruel and power mad, they are the dangerous ruler of the Old Builder World. They manipulated things in their favor so Jesse couldn't make or use better weapons against them in the final fight. Their building skills, combat pragmatism, dirty fighting and own experience with fighting makes them the only villains who defeats Jesse in combat. And Jesse would have died if there wasn't the respawn system and would have lost if his friends wasn't around to help him. Thus essentially they only got defeated by their own invention.
Just my opinions. 
Comments
PAMA and Cassie Rose/White Pumpkin are tied as my number 1, both at a 8.5/10. PAMA because, like you said, he was creepy and definitely the most dangerous of all the villains we faced (yes, including the Witherstorm). As for Cassie, she was driven by her want to go home and fear of being trapped in an unknown world, and it drove her to somewhat insanity. She took some drastic measures, like murder, but for some reason, I admire the amount of thought she put into her plan and the elaborate traps she laid out across the mansion. Doing a murder mystery is something I was not expecting from a kids game like Minecraft, so I'll give it that.
The rest of the villains were kind of bland in my opinion. I guess the next one would be The Wither Storm (7/10), as it was a constant threat and, for a while, seemed unbeatable, even after we used the F-Bomb on it (that name still gives me a chuckle). Also, it killed Reuben.
Hadrian (6.5/`10) and Mevia (5/10). Hadrian got his time to shine, we kind of understood why he wanted to keep the contestants there and his ability to sort of change the rules or manipulate the game to his liking, but with Mevia, she just kind of went along for the ride, we didn't get to see a lot of her and she is pretty much just Hadrian's right hand man (or woman), nothing else about her other than that. It was always Hadrian pulling the strings, but Mevia was just kind of there.
Aiden (6/10). He was driven by his jealousy, but at times, it didn't feel like it made a lot of sense and felt like a forced conflict. Especially if you let Lukas go in Episode 4 and he and the other Blaze Rods help out during the final fight with The Wither Storm. Plus, what was his plan after taking control of Sky City, just destroy it, but why? What good would come from that? He even knows that the place was going to shit, but he not only let it happen, he helped in it. And at times, the jealousy felt very childish, like a child screaming at his parents that he wants a new toy but the parents say no, he thinks he's entitled and deserves it. Yeah the final fight was good, but Aiden just wasn't that good of a villain.
Ivor (2/10). Pretty much the same reasons you listed.
Ivor, villain-wise, is my least favorite villain. It was just a case of "oh-he-made-the-monster-so-we-have-to-hate-him." That is, until he helps out in defeating the Wither Storm, and joins Jesse's group for the remainder of the series. He ascended from becoming a mediocre villain, to a HIGHLY praised fan-favorite.
The Wither Storm is honestly my second least favorite villain. It was an awesomely creative monster that sees nothing but destruction, and it's final battle will always be remembered...even if it did kill our favorite pork-cho-I mean, pig. However, the reason why it's my second least, is because we only fight it in four episodes, and it was set to be the main story arc, so yeah.
Hadrian and Mevia, altogether, are my third favorite. I mean, first off, Hadrian is a great human villain, not as good as Cassie or Aiden, but still a great villain nonetheless. All he wants is power, domination, and slaves, all what a villain really wants. Mevia, however, she's just Hadrian's loyal bitch.
Cassie and Aiden are tied for second favorite. Aiden, for starters, just passed off as a regular bully at the start, but with the Storm gone, he REALLY let his true colors flow. I respect Aiden as a villain, not because of his intentions, but because of his personality change. Like I said, at first, all he wanted to do is to make fun of Jesse, but now, he. Wants. Jesse. DEAD. Cassie is almost like Aiden, started off normal, then went completely insane, taking on a persona we all know as The White Pumpkin. And all she wanted was to go home.
PAMA is my favorite villain in the series. First off, he's basically redstone HAL. He's a sentient computer who went overboard from his duties and wanted to make EVERYTHING useful. He's also responsible for almost killing Lukas and/or Petra.
PAMA: 10/10
Old Builders: 9/10
The White Pumpkin: 2/10
Aiden: 5/10
Wither Storm: 8/10
Yes I hate Cassie, she killed her own friends.
Hadrian and Mevia - 8.5/10 - I really liked how direct, sarcastic, and rude, Hadrian and Mevia were. It especially helped they got a actor whose really good at playing asshole characters to voice him.
PAMA - 7.5/10 - I liked PAMA, but they never came off as a huge threat. The battle at the end with them is intense, but its more has to do with people being controlled over PAMA. I mean they did it of course, but eh.
Witherstorm - 9/10 - I REALLY liked the witherstorm because it had no exact goal, it was a mindless beast made to destroy everything in its path, and too me environmental hazards have always seemed more scary.
The White Pumpkin - 9.5/10 - I REALLY liked Cassie Rose because she got the job done for the most part. She actually killed people. They died. She's also wickedly crazy. and pretty clever even if her loneliness held her back from being the ultimate foe for Jesse and friends.
Aiden - 5/10 - Aiden was really lame in my opinion. He seemed more like a chaotic neutral. Just a salty baby who didn't get what he wanted, and when he's challenged and loses he begs for his life. What a chump.
Oh right Ivor...Uh...2/10? - He was a villain for like what 3 episodes?, but we only saw him in 2 of those 3, and he didn't even show up till the end of one of those episodes.
PAMA: 8/10. I liked it because you can never really make computers in real minecraft, it was a really cool but evil computer.
Ivor: 4/10, why would someone spawn a WITHER just because he was kicked out of the order of the stone and they cheated by teleporting the ender dragon? He could've just told everyone the story of them fighting the ender dragon isn't real? But the not evil Ivor was one of my favorite characters.
Mevia and Hadrien: 9/10. Really different villains unlike from other episodes, they were really harsh and had no mercy, they enjoy watching people play games and die for fun, then send them to the mines for an eternity. I like how rude they are compared to other villains.
Aiden and the Blaze Rods: 5/10 Just a bunch of jealous people who will do anything to gain power and kill Jesse. I didn't really like them.
Cassie Rose: 10/10. She's my most favorite villain, because she trapped people in her mansion only to get the enchanted flint and steel and go back home. She could've just asked for it. She was a really evil and crazy murderer. Pretty evil for a girl huh?
The Witherstorm: 7/10, it's just a crazy monster that just goes around swallowing and destroying everything in its way, but a really good villain for the first few episodes.
Ivor: 1/10 Cause' he wanted to just show the people what he could do, he said he was about to stop the Wither but Axel stole the potion
The Blaze Rods: 4/10 They are just some derps who belive they're cool but they're not. Look at episode 5 when Jesse hit Aiden with the sword at the Sky City he apologized, the other 2 guys are just like "bots" they follow Aiden everywhere
Wither Storm: 7/10 is big and scary and can get even bigger and the best of all: its made out of obsidian and COMMAND BLOX!
PAMA: 10/10 Is a 4 BIT COMPUTER! Yeah I know its 4 bit cause' the arrays of buses were just 4, so I guess its 4 bit. Its the most smart and scary thing I've ever saw and it can process data in 3 ticks or so.
Cassie Rose: 6/10 She is good at fighting but I dont like her clothes, since she looks like a derpy miner with a pumpkin head, btw also good redstone skills but nothing compared to mines since I built a working 6 bit CPU with GPU in minecraft. The GPU has its own custom ICA adder so it runs Bresenham's Line Algorithm, also it has a BCD decoder so ya can read numbers in a 7 segment. ALU can Add/substrackt and all logic gates. Data Flip Flop based storage and an easy to use interface. Also it has RISC ISA and its not opcoded, sorry :P
Mevia and Hadrian: 9/10 Good fighters and Pro liars. They enjoy watching people hate eachother and killing themselfs. I was sad when Lucas and Petra fell to the piston thingy at spleef but I got angry when Hadrian said that he will send them to the mines, forever