Deep in Baldur's Gate 3's mammoth patch notes for its fifth main update is a whammy of a line: "Minthara will still appear in Moonrise Towers if she was knocked out in Act 1." That's right, it's now easier than ever to recruit Baldur's Gate 3's "evil" companion without committing to an evil playthrough. Spoilers for Act 1 below.
About halfway through BG3's first act, you can side with either Silvanus' Grove or a marauding goblin tribe, with the former eventually netting you hunky druid Halsin as a companion, and the latter resulting in the friendship of Drow hardass Minthara. The goblin path is pretty heinous, so a lot of players (myself included) have missed out on Minthara's unique character arc and romance subplot—she placed dead last in our ranking of Baldur's Gate 3 companions for just this reason.
Previously, you could turn to mods to recruit Minthara on a good playthrough or, amusingly, go through a whole speedrunny-break the game gauntlet that involved polymorphing Minthara into a sheep and carrying her to her date with destiny in Moonrise Towers. Now, though, you just need to use Baldur's Gate 3's non lethal attacks to knock Minthara out, and she'll make her way there on her own.
As outlined by zanyquack on the Baldur's Gate 3 subreddit, it appears that talking to Minthara in Act 1 currently precludes her showing up in Act 2 if you try this route, so you have to knock her out without initiating dialogue to get it to work. It also still doesn't seem like "the way the game was meant to be played"—Minthara and Halsin don't really acknowledge each other's existence once recruited.
I'm of two minds about this—I love friction in an RPG, and having mutually exclusive party members complicating what's otherwise a pretty cut and dry moral [[link]] choice is such an interesting thing to have to wrangle with. On the other hand, Larian already rewards creative problem solving like clever use of non lethal attacks—you can prevent an otherwise-inevitable murder as the Dark Urge by just knocking your target out at the right time, for example.
Also? I'm a huge softy and could never betray the Tiefling refugees, so this is the only way I'll ever see Minthara's story. Not this playthrough, though: I'm 15 hours deep in the permadeath Honour Mode and working on wiping out the goblin leaders. I don't have the luxury of testing some funky new technique like this. Sorry Minthara, but my party's about to do heinous things to you and your goblin buddies with an explosive barrel.