Atomix doesn't need to use his energy to beat anyone. He kicked Gwen and Kevin into space and beat Ultimate Humungosaur and Ultimate Spidermonkey, and survived getting punched into another planet, which neither Feedback nor Chromastone are able to do or survive.
Waybig also threw Vilgax into space with ease.
The second options because it has some of my favorite aliens.
OV, because I would transform into any alien I want without glitches, have more aliens, and select aliens much quicker.
They both can go intangible, and it was shown that an intangible Necrofriggian can still fight another intangible Necrofriggian, so I don't see why Big Chill wouldn't be able to fight Ghostfreak or vice versa. Big Chill has more powers and would probably win because of that. I don't believe Ghostfreak could posess Big Chill.
Depends on what you mean by strongest. Shocksquatch is physically the strongest, but Feedback is the most powerful.
Diamondhead is not made of Tadenite or Diamond. His shards are weaker than both Diamonds and Tadenite, which is why we've seen them break countless times. Four Arms is stronger and more durable than Diamondhead, which is why Ben always used him when he needs to do some heavy lifting or punching.
Alien Force: Alien X
Ultimate Alien: NRG
Reboot: Shock Rock
I would watch all the episodes I could and collect all the toys I want and keep it in my heart.
The Upgraded one from season 2
Upgrade, but I miss him a little less since Glitch Ben exists
This is a tough one. If Human torch stalls, Big Chill could go intangible immediately and possibly win. If Human Torch attacks right away, he'd probably get a big enough hit on Big Chill before he can go intangible and probably beat him.
I like your suggestions. One suggestion I have is to have Ben travel to other alien planets. We've seen the planets and lore for his aliens, but I think it would be awesome if Ben could visit some of those planets. Another suggestion is to have an arc with continuing episodes that are related, similar to Ultimate Alien Season 1. They sort of did this with S3, but there were still a few filler episodes. It would be nice to have an arc full of no filler and a big story.
Okay, thanks for the clarification
If we are talking Alien X vs Paradox, X would win for sure.