Thanks a lot! I really liked those guides from the olden times too. But I can't take all of the credits,
Holy Bacchus gave me the idea for the character cards. From there it just grew into this whole thing.
The plan is to handle the harem very much like Sisterly Lust. The trouble is that the story isn't in a place where a harem could be formed, because most of the romantic relationships haven't developed fully yet. In Sisterly Lust the harem stuff happened past the halfway point of the game, well after they visited the Fantasy Island of Incesty Delights.
Tales From The Unending Void is a bigger story, so the harem stuff will likely evolve at a later stage. I don't want to go into too much detail, but the game will most likely have three big story arcs (
Getting Eva back is one of those arcs.). I plan on having a lot of the individual romances in play near the end of the first arc and create the beginning of a harem at the start of the second arc (
Céline and Jade are two likely early candidates, but there might be others.). That will develop further during the second act, culminating in the third act with a full harem and a whole lot of intermingling (aka fucking). Other gentlemen won't touch the harem in any way, except maybe for a rare optional scene, like the double penetration of Ana in Sisterly Lust. But lesbian group sex between the girls in the harem is of course a given.
I want to aim for that loving feeling you describe in the group scenes here as well, because that's what I like personally as well. Less fond of the isolated fucking where everybody is oblivious of one another.
Hope I can pull it off though, I'm getting "pregnant-harem-variation-render"-nightmares already.