- Alexia: templates to clear the risen out. A bloat thrall can hit the DEF of a risen. Purge some bile thralls over her and see how many risen fall and corrosion will help a great deal too. And remember that you can't target alexia with a spell, but you can target risen, and and AOE spell can damage Alexia too if you target a risen near her.
- Keep a good commander like tartarus or rengrave near your troops.
And I don't think she can take over undead after she ran, but I have to double check that. Basically it's because after a model runs, his or her activation ends. But as that command undead isn't a special action but an abillity, I'm not sure.
@ Skrit: If you want to play, let me know