While its true that DTombs doesn't 'require' a destructive domain, it is so fricken expensive (200 points) that if you want to do anything with magic on your pretender you almost have to take a destructive domain, or at least a domain with negatives.
Though in fairness, DTombs can handle alot of negative scales fairly well...
Miasma is interesting, though maybe a poor selection for MP since your domain effect is going to tick off your neighbors, probably worse than Ermor ever did. I've been fooling around with it for fun though, havn't quite figured it out very well yet though
