Need help running a solo necromancy-based campaign

[Totema]

This is kind of a complex situation, so let me explain: I tried setting up a new campaign with a group of four friends who either had never played D&D at all before, or only had limited experience with it. At first, things were looking great, but gradually all but one decided not to play. (Incidentally, he was the one who already had some experience.) So at first, I figured we couldn't play at all, but then I decided to treat him to a solo campaign that would act as sort of a prologue to the original that I thought of. I decided it would be fun to set him up as the villain, who would have turned out to be a powerful, high-level lich necromancer. I ran a couple of sessions and we're having a great time, but I'm running into a couple of issues.

First, adventures are becoming a little monotonous. We've been doing some the same "explore a tomb to find undead followers" thing for a while, and it's starting to wear a little thin. Does anyone have any suggestions to make the experience more interesting?

Second, we're finding that playing in this style is a little inconvenient. Considering that it's a solo campaign that sound a little obvious, but for one thing, I'm finding that the game doesn't seem to provide a lot for the necromancer-type character. I had to make a ham-fisted homebrew ability just to allow him to make new undead allies (the Dominate Person spell doesn't seem to help for making permanent friends), and my player is a little disappointed that he has to personally find a boatload of corpses to make his prized undead army. Are there ways to make playing as this type of character seem more fulfilling?

I realize that these questions are kind of vague, so I can provide additional contextualization if needed. Thanks!

[Corndog]

if your issue is that tomb exploration is becoming monotonous and finding bodies is becoming monotonous, then you should have him get his hands dirty (or dirtier)

maybe you could have him take a visit to some town where his goal is to undeadify the inhabitants
he could poison their well and reanimate the victims or something

[Humble Master]

Well if he is lacking in Undead minions, getting Rebuke Undead is very helpful. Also, what class is he?

Some adventure ideas:
Raid a town for supplies/bodies/fun.
Attack a secret library to uncover a mysterious necrotic spell/ritual
Get work with the church of Wee-Jas as a mercenary to kill someone/something.
Have to deal with good guys.
Work to build a Cadaver Collector. It is a Necromancer's best friend.
http://www.wizards.com/dnd/images/iw_cadaver_collector.jpg

[Totema]

We eventually decided to make him a True Necromancer, from Libris Mortis. This worked nicely because he wanted to dabble in both divine and arcane magic.

[Malroth]

Order of Paladin's find out about his evil deeds and show up to try and stop him, make sure each member of the order has an age appropiate younger sibling (aka the next generation of PCs) to get revenge after he destroys them all

[Waker]

I would say that it is time to start sending some good guys after this BBEG. Maybe give him the option of recruiting one or more of them to his side as a lieutenant. Or how about setting up a base of operations? It may be time to set up shop in a nice crypt or clear out a slightly occupied church and refurbish it for your needs. Make a pact with a vampire buddy to blot out the sun in a countryside so you guys can have an all-night party that lasts for years.

[BowStreetRunner]

I would agree that your campaign seems ripe for a bunch of good guys to show up - whether it is an angry pitchfork-and-torch-wielding mob, the local lord and his retainers, the Spanish Inquisition (nobody ever expects them!), or some combination of these, his encounters should include having to wage his private war against the forces of good. It might even be fun to throw a party of adventurers at him.

Another element you can introduce are allies. Not necessarily a bunch of chums for him to buddy around with. More like the old 'enemy of my enemy is my friend' type allies - people who are not in a good relationship with the local mob, the lord, the church, or whoever is after the necromancer. These might include:

A local group of bandits who may occasionally have goals that align with the necromancer's.
A corrupt gravedigger willing to provide the necromancer with bodies (and fill their coffins with stones when he buries them so no one will know) in exchange for lessons in 'black magic'.
A black marketeer who not only will help provide the necromancer with some of the less savory spell components he needs, but also has a list of requests from other customers that the necromancer might be able to help fill. (Good side quest material.)
An assassin's guild whose fortified redoubt is located in the nearby hills. They consider necromancers to be useful allies to have, and will sometimes come to him for various needs. (Good side quest material.)

[Totema]

Awesome, I'm getting some great ideas for adventure hooks! But my player feels a little limited by his ability to grow his undead army. For example, one thing that he's done to make powerful political allies is to use dominate person on them, force them to become necropolitans, then gain their permanent allegiance by rebuking them, but this seems pretty clunky to the both of us. Is there a more elegant, rules-compliant way to do this? He also doesn't particularly like the apparent limit to the amount of undead he can control - we eventually want to give him control of an entire army of undead. Is there something we're overlooking?

[Waker]

Awesome, I'm getting some great ideas for adventure hooks! But my player feels a little limited by his ability to grow his undead army. For example, one thing that he's done to make powerful political allies is to use dominate person on them, force them to become necropolitans, then gain their permanent allegiance by rebuking them, but this seems pretty clunky to the both of us. Is there a more elegant, rules-compliant way to do this? He also doesn't particularly like the apparent limit to the amount of undead he can control - we eventually want to give him control of an entire army of undead. Is there something we're overlooking?

You could start a Rebuke Chain. It's sort of a Pyramid Scheme, but you needn't involve mummies if you don't like them. Basically you Rebuke an Undead Cleric and he Rebukes his own Undead minions. So you control the Clerics (or Blackguard, Dread Necromancer...) while they control the rank and file corpses.

[Malroth]

Plus uncontrolled undead are also useful, just bunch in 1 or 2 controlled undead archers to get the hero's atteention surronded by a bunch of big angry mindless undead that just attack any living thing near them and ignore your controlled ones.