From everything I have seen, I gathered that after you beat the evil wizard construct you can tell Nordom to become stronger and stuff. However, after I beat him, I don't seem to have any new dialogue options with Nordom. Am I required to do something?

You have to convince Nordom that you are the director. When you do this you can have him improve some stats at the expense of others. You have to talk to him as a fighter,mage and thief to get each change. If I remember correctly you have to a high Int. score to do this though.

You are required.
Required to ask Evil Wizard Construct about EVERYTHING before you start the fight.

Have you talked to him about everything?

More details (spoilers) on the topic you may find here:
http://www.sorcerers.net/ubb/Forum3/HTML/000083.html

EVERYTHING?

......*sigh* guess I'll have to reload...in the bloody Dead Nations.....ARGH! I was so lucky to go to the wizard in only ONE part of the maze...ARGH! ARGH! ARGH!

for help on this (and any other NPC dialogue thing) go here: http://www.sorcerers.net/Games/Torment/npc_convos.htm
this is a compilation of all NPC dialogue options that give you something and what is required for them.
-FenixStrife

Actually I don't believe you have to reload.You can just create a new dungeon on the hard setting and the wizard should be there again and you can go through all the dialoge this time.