Aura of the Lich is a good elite, if you only have prophecies. Bone horrors and bone fiends are your main minion skills. Bone fiends do better damage, but are ranged attackers, so they won't be a good meat shield. Bone horrors are better for that role. Dark bond (blood magic spell) is also a nice skill, which is often overlooked.
Death nova could add some damage if you care to keep busy with that... you can take taste of death to chose when to make a minion go boom.
The rest would be fillers in the form of some direct damage death magic spells, such as deadly swarm. Or support skills for your team, most likely protection prayer spells such as protective spirit and/or aegis.
Even with the limitation of only having access to prophecies skills, you can still make a decent meatshield that deals some damage. Have fun ^^