Asterisk passed away a week ago from ammonia poisoning. There was an incredible spike and he was almost completely rotted away by morning, I couldn't understand it.
However, before his death, he got along perfectly with the tetras. Just like with the guppies, they each had their own 'space' in the tanks. Asterisk would swim around and rest on his little log and the other fish got the rest of the tank. Unlike the guppies, these guys didn't try to eat all his food and did not continuously try to school with him (silly guppies!).
I realize it was a pretty gutsy move, but he actually seemed to become less agressive with each new tank mate and certainly became much less frantic.
When I started out with the first guppies (Thor and Loki) Asterisk chased them around a bit at first, but quickly lost intrest. Thor tripled in size, but Loki remained tiny, only his fins grew and would wedge himself in between the gravel. Eventually, I decided to add more guppies because they were coexisting well, but the Thor and Loki were clearly uncomfortable. I put in two males (Frigga and Odin) and, much to my surprise, Asterisk had no reaction at all. Thor immediately perked up but tiny Loki still would push himself into the gravel at the bottom of the tank. He wasn't sick, and still exhibits that behavior today. The last addition was Balder, a leopard guppy, who when added didn't want to be with the other guppies, but rather would school with Asterisk and rub against his sides. I always assumed it was because he was so large and maybe thought Asterisk was one of him? Asterisk never attacked him, only moved away when Balder stuck around for too long.
Anyway, despite the tanks success, I don't think I'll be repeating it. I wouldn't want to risk getting an agressive betta and harming my other fish.