"Do the nominated relationships have to be healthy? Because this is not. Toxic yuri to the max. You can either have it with one side brainwashed to do the other's bidding, or after, where it'd surely end horribly, in death of at least one of the parties. Orin is messed up beyond help, and Minthara isn't merciful. Which can be juicy."
"What's better than Wyll and Astarion? Or Astarion and Karlach? Or Karlach and Wyll? All three together, that's what. First, there are the narrative parallels. All three are Baldurians with a very different experience of Baldur's Gate. All three had their bodies forcibly changed by their abusers, and all three have unwilling ties to Avernus and devils, with narratives aimed at subverting what they believe they want (Ascension for Astarion, to save his father for Wyll, and revenge for Karlach). Then, they all work amazingly as individual component ships - Karlach is openly attracted to (and fiercely protective of) Astarion and Astarion is gentler with Karlach than anyone else, Karlach and Wyll's narratives are intrinsically linked and they're more or less soulmates, platonic or otherwise, and Astarion and Wyll are so down bad each other it's hilarious.
But what about as a trio? There's one tempting in-game crumb, only available if you play as Origin Karlach - after Astarion points out that Wyll giving Karlach the benefit of the doubt and all it earned him was a set of horns, he adds, "Not that they don't look flattering on him - almost everything does", with a lovesick little sigh. Karlach can then comment, "They do look pretty good, don't they?" to which Astarion can reply, "They do! Honestly, that man…" with an even more lovesick sigh. This conversation only being available with Origin Karlach at least says to me that Astarion recognises that Karlach is just as down bad as he is, and therefore he's more than happy to share those, like I said, lovesick sighs.
They work well together. Wyll can be on the serious side; Astarion and Karlach are both traumatised, but both know how to have fun (even if that fun sometimes involves stabbin', for Astarion… come to think of it, for Karlach too). Astarion can be cruel, through nearly two centuries of his empathy being systematically dismantled; Karlach and Wyll are both genuinely good people who can drag him, kicking and screaming, into caring for people. Karlach can be hot-headed and angry; Wyll can be calm, Astarion can help her focus her anger into something productive. They make each other better.
And, their endings all work beautifully together. Wyll openly begs Karlach to go back to Avernus to save her own life, promising he'll be there right there at her side. And Astarion, when romanced by Origin Karlach, outright says that Avernus is perfect for him - there's no sun, he can hunt as much as he likes… and he'll be with the people he cares most about. The three of them work together in a stable triangle, each point supporting the other, none of them letting one of the others fall."
