Thomas Mercury, dubbed "Thomas Mercury Thunder" by his friends, is a member of the Hero Factory Recon team. He is very intelligent, and seems fairly calm.
Thomas Mercury is capable of doing extremely complicated sums in seconds, and yet can't shoot a target unless he concentrates. Usually the hero for concentration, he can hit it a good dozen times... but when distracted he'll hit anything, including other heroes. Because of that, he was given a simple, low-level gun without much ammo and put on the Recon Team, where his cool, calm analysis would come into play.
During the Von Nebula incident, he had not yet been created, though designs for him were in the works.
Thomas first came into action during the events of the Fire Lord attacking, though he was still a rookie. And while he has superior skills in intelligence, he's not exactly a crack shot, since he misses the target (and sometimes hits other heroes, usually Stormer) a good deal. Despite this, he makes it past his basic training to join the Recon Team along with Merick Fortez and as the Recon Team grows and time passes, the two make good friends.
During the Quatros incident, Thomas was busy trying to get a 3.0 upgrade like Fortez. However, he was told by Mr. Makuhero that he's a fine hero even if he's only in the 2.0 upgrade. While he is pondering what Makuhero meant, and whether it has to do with the fact that he'd be dangerous with a more powerful gun, the heroes came home from Quatros and greeted him warmly after a good victory.
- William Furno: Thomas and Furno's relationship is fairly business-like, the pair never really see eachother much and both are usually busy doing their own thing, but Furno acknowledges Thomas' intellect and in an argument, he tends to take his side.
- Mark Surge: Thomas' relationship with Surge is fairly stretched; while Surge is a very nice person, the two don't get on well due to their different element associations (Water and Lightning respectively) and neither one really has time to get to know the other, so they're stuck in a business-like fog with one another.
- Natalie Breez: Thomas has a slight crush on Breez and likes her 2.0 upgrade. The two spend a bit of time together during the Quatros incident and get closer, though Merrick Fortis intervenes later on and claims that "She only has eyes for Furno." Disheartened by this, Thomas hasn't spoken to her for a while, which upsets Breez.
- Preston Stormer: Stormer doesn't like Thomas much. Oftentimes he's the result of Thomas' misfires and he has a decidedly business-like relationship with him. Due to this cold treatment, Thomas steers clear of him.
- Dunkan Bulk: Despite being complete opposites, (Thomas relies on smarts and trickery, Bulk tends to be more strength based) Bulk and Thomas are friends. When Bulk is called out on a mission with his good friend Stringer and when Fortez and Breez aren't around, he sits near the loading dock, waiting for him to return.
- Jimi Stringer: Thomas doesn't know Stringer that well, but idolizes him thanks to Bulk.Stringer wants to know more about Thomas
- Nathan Evo: Thomas didn't know Evo that well as he was shipped out to fight the Fire Lord before he got a chance, and during Quatros Evo was just hanging around waiting for his "twin" Nex to come back, and praying he's alive.
- Julius Nex: Thomas doesn't know Nex at all, due to him being away during and after his creation with Fire Lord and Quatros.
- Rocka: Even though Rocka was away on Quatros for a time, Thomas and Rocka made friends when Rocka was 2.0. Merrick recognized them as good friends, and Rocka enjoys spending time with both Thomas and Merrick.