[quote=@Polybius]

I really dig this setting and the characters that have already been submitted. While my writing skills are a bit rusty, I would love to give this a go. 

A few questions that may or may not be necessary to answer:

1. How do you, and can you kill an undead?
2. What is the source of necrotic power in this world? 
3. Are there any gods/religions of note?
4. What currency if any is circulated? 

Thanks!
[/quote]

First of all, it is great to see you again Poly! Sybax is gladly accepted and being so close, I hope to interact with him regularly. In response to your questions:

1. Undead are exceedingly difficult to "kill" as one would expect. Hacking an arm off will almost certainly kill a living warrior due to blood loss and shock, but an undead warrior will continue fighting. This is why the undead were able to conquer all of Leria with only a handful of notable defeats. Decapitation is perhaps the easiest way to dispatch undead - the body will collapse but the head may still continue to function. Complete destruction of the head is the only way to actually kill an undead with purely physical means, and is wonderfully illustrated in Oraculum's first post. Theleden, as a living warrior against the undead, used fire to destroy large swathes of undead at Esteline and Sour Bridge, either by completely immolating them or burning them to the point that they were no longer capable of fighting. There may also be some magical means of destroying undead. Perhaps there is a way to siphon the necrotic power out of a cadaver. I haven't considered such a possibility until now, but am open to such a thing so long as it is extremely rare/difficult to accomplish.

2. Undead are reanimated by the power of the Ritual of Undeath. Eagoth first discovered this phenomenon and recognized its potential. It is a very magic-intensive spell, and so only very powerful wizards like Eagoth are able to accomplish it. Eagoth eventually was able to delegate the Ritual to his undead lackies by supplying them with crystals imbued with arcane power. Eagoth saw handing over what were essentially batteries full of arcane energy as a liability, and stopped doing this. He now collects energy from the Spire of Rutile to continuously pump necrotic power into the earth via the lightning strikes illustrated in my first post.

3. Cyclone's first post mentions Zealots in a realm called Luminara, which implies some sort of religious crusade against the Undeath. There is also Incredible John's quasi-religion that depicts Eagoth as a messiah of sorts. Additionally, my first post shows that there was some sort of religious institution in Leria prior to the Undeath. The God(s) it revered, or what it stood for, are probably almost completely forgotten by the undead.

4. Cyclone has hit the nail on the head and I will refer you to his answer on this.