So I had this come up in a game recently and was uncertain how it would work. My opponent was running the twins (Lelu & Lilitu) and I had Tuco successfully cast Taint Loyalty on Lelu thus making him not friendly to any other model. Taint Loyalty has no duration and thus ends in the Resolve Effects step, however given Lelu/Lilitu take damage in the Resolve Effects step if no friendly Lelu/Lilitu is in play.
The question is which happens first, the spell expiring or the 3 dg taken for not having a friendly Lelu/Lilitu in play?
We played it out as "Lelu was unfriendly going in, so the twins both took the damage and the spell ends going out of the step" but the rulebook was little unclear regarding this kind of scenario so I leave it to the community for thoughts/comments.