The Ballad of Adler Young, Canto 2.5

And couldn't Estmere use the same method (or have it used on him by Estvan, or someone else) to make an heir instead of having to rely on the Vulpitanians?

I believe the question was already raised since Addler did have Ixie kid while turned into an ixie.

The thing is, Estmere mother has been tainted by the Archfaix arch and so he's not a 'true' elf anymore; we've never seen him use much magick and it's possible he can't do somethign as elaborate as turn himself into somethign else.

Queen Adriesta miiight but she's keeping her secrets well guarded. And anyway estmere will refuse to hump her if she looks anything than an ungulmate due to sisterhood conditioning.(Maybe if he closed his eyes and puckered up buuut.. he seems pretty uncooperative and kinda childish.)

And of course he's surounded by sisterhood ministers who are going to make sure she doesn't do that (since they want Adller on the throne), Vulpitians (who want to destabilize the ampire and i'm wondering if they don't want Addler ont he throne fior their own reason as well)

Also It's been a whiiile (and I really expect we'd hear more about this by now, really) but I remember it was a big deal that the fuma archpriest or something was seriously anti magic, up to the point that he rather let the king die rather than let the doctor use gramayre to neutralize the poison, so there'd be the problem of the legitimacy of the children.

Add to that the fact that elves are pretty unfertile in the first place (that was the whole point, officialy, of the fairfax arc). and yeah, I wouldn't bet on his succession being too numerous.