Tempest is a chatty fellow, to put it mildly.
When Reach and Tempest are in the same picture, Reach lets Tempest do the talking, because Reach is actually not that talkative unless they have to be. So if your muse wants to get a few words out of Reach when both are around, they may have to tell Tempest to zip it.
See, Tempest means no harm. He realized early that Reach is a quiet one, so he happily jumps in for them when it comes to conversations. Though, ever since Reach told Tempest to shut up once when he got ahead of himself again, he tries to give Reach more space, at least. But usually, he's the one talking a storm out of the two, and Reach is usually fine with that too.
Tempest is also very fidgety. He doesn't talk and stand still, that just doesn't happen. He's shadow-boxing, jabs fingers into the air, is very dramatic in a theater kid way and overall very expressive and perky. The opposite of Reach.
Don't get fooled though, him cracking jokes and facing horrors with a positive attitude is his way of coping with the terrors around him and dealing with his fears. He is in fact scared a lot, but decides to face his fears head-on rather than walking away. That's how he does things.
It's hard to not like Tempest in one way or another, he's just that cool and nice guy, even if his antics can and WILL drive one up the walls. He is absolutely reckless and acts before he thinks. Which gets him into sticky situations a lot, but he's a survivor. He claws his way out of trouble, if he has to.
Speaking of survivor, he's a 'Disposal', which means the corp stole one of his organs and then disposed of him like trash. I don't think it is ever mentioned what organ was taken from Tempest, but since it is not something visible and not actively hindering, I'll go with a kidney here. I will edit that if needed though, should I have overlooked a detail.