If you can live without the monster, replace the Undead Champion with the Ghost Undead Knight, and if you can't live wihtout it, Replace the Ghost Undead Knight with the Undead Champion.

Personally, I felt the ghost variants never added much to the game. In my opinion, it would've been better to introduce one or two completely different monsters with that +Ghost gimmick.

The Undead Warrior Ghost almost is a new monster, being that it skips the green axes entirely. Especially when mobbed together, their axes pass through their comrades and make for quite a volley.

Golem ghosts are nigh pointless when placed in high-visibility areas. Typically they end up just being more annoying to kill, since the Crossbow's small arrows are going right through them and diminishing the already slim chance of one-shotting.

It's not until they're paired with Undead Warriors that they really start getting interesting. When your Golems are frontlining, you can't have them shielding you from flying axes. Strategy!

They're also suitable when placed in dim areas textured in a similar color. The camouflage effect makes it all the more necessary to use your ears.

Going back to Starscream's suggestion, I think it's been well-established how happy we are about modifying the existing monsters too much.

Well, Blue Shadow is very awesomely making a new set for the Undead Champion. Dual-axes, a new helmet, and shoulder-pads edited from the Hexen Fighter's armor. It looks quite good.

Im quite eager for the new champion! More green axes, what type of attack? What would them blue do?

Still if it ain't broke don't fix it, and I like these new sprites.

I'm thinking just red and blue axes. Blue, I'm not sure what they'll do, yet.

I'd suggest red, just as the red ones from the shadow knight. Having a third color just turns into a circus.

If it had blue axes, they'd have to be electric I guess (like Timon's Axe in Hexen). Better to stay with red and green though.

He could fire them two at a time, like a mancubus.

Two of them like the Mancu sounds lame... but what about making him throw more than one but in a curve instead of flying towards the player like a projectile? Maybe a curve towards the player where the axe drops green acid while being in the air so if the player dodges towards and under the axe, he could still be hurt?

Hmm, could this be done with some slight A_Weave trickery? I don't know enough about A_Weave to do this, however. Though, I'm concerned it might not work well in a hallway, or if it was close to a wall.