Glavinage

I think you got confused, in the example Izamu is the friendly undead model that is being attacked, since Izamu is Ht 3, Kirai has LOS for her Aura. So OP would be allowed to summon Ikiryo, also Ht 3, in their example.

I'm not particularly familiar with Ressers, but at first glance it seems that Mourners may be decent with Molly as a summon, summon them in your opponents face and use Molly's zero to put up Funeral Shroud, it at least seems like a use for them, but as hires I'm not so sure.