Terry is an awful fucking person and I don't really talk about it much in detail.

It is CONSTANTLY helped and saved by Dana. She will go out of her way to help it and ensure its safety, yet it never reciprocates that in any form. The complete opposite. This is an example out of MANY, but in chapter two of what I'm writing, Terry leaves Dana to deal with a handful of thumpers and a coil alone. Dana still defends it [ in the literal sense ], and until Daniel's arrival, she brushed it off. After his first appearance though, she realizes that Terry doesn't give a shit if she's left behind. Dana really doesn't want to see Terry as a bad person, as it was the one to sorta teach her the ropes- albeit not of its own choice- and she considers it a friend, but it's REALLY hard to do that when one of your co-workers is getting freaky with creature that could kill your whole crew if he felt like it. Their relationship declines throughout the story.
[ I believe there are four-ish chapters where Terry straight up leaves her/everyone, although it does worse than abandon her. That's spoiler territory though 😋 ]

Ulan learned pretty fast that Terry's shit when it comes to reliability. [ He's aware of Terry's habit prior to the time the story takes place as he's worked with it for a while. ] He frankly doesn't care, as long as Terry gets shit back to ship like its supposed to, it can do whatever it likes. The only thing that get's on his nerves is Terry calling ship when there's still people off ship. In general, the two have come to an unspoken agreement that they don't help each other out aside from basic shit [ ex: teleporting if they really need it, opening the door if it's closed, helping with carrying scrap ]. Anything that requires them to go out of way for each other is off the table.

Daniel doesn't help with this at all. If anything, he encourages it. He is fuel for Terry's horrible habits. Sometimes it's directly influencing, other times he simply lets it do whatever it wants. They are TERRIBLE for each other, and both of them are very aware; Daniel a bit more than Terry. Daniel actively points out they are bad for each other SO MANY TIMES. This doesn't stop him from wanting to be with Terry [ Daniel being Daniel ], neither Terry wanting Daniel [ BPD].

Little additional to this: If Daniel was alive, Terry wouldn't have a chance. Daniel would have hated it when he was alive.

Terry gets worse before it gets better. It does eventually try to work on itself, but a majority of it happens towards the end/after the end.

Oh, also, Dana is the only one that gets a happy ending. 🎉🎉🎉🎉🎉🎉