Utterly Mad

Lore wise the reasons for Sentient undead is wide and varied. In the original version Harrow was raised by several of his fellow Magi after he was purposefully killed, however he had refused to remember some of the events that had transpired.
We had a character (I think made by Hibou) who was raised by some kind of fungus or something like that.
And some of them are simply dead who refuse ot enter the gates of death and instead force their way back to life(usually pissing off a god or two in the process).
so a rare form of Lichen would work too.

Again, pretty well free form here, so feel free to write up lore if you want. I'll be posting a sheet tomorrow.


Magic techniques I've made
Mage Tongue (all users are born with an innate affinity to magic)
A complicated language that harness the power of the world around the magi and focuses it into the desired effect. often spells require chanting or a quick, precise sentence. Chanting can take a half minute to multiple hours, even days depending on the spell.

Death Tongue (all users are born with an innate affinity to magic)
To be a Death Tongue requires several years of devotion followed by a ritual in which they remove the acolytes tongue. Death Tongues devote their lives, bodies, and souls to their work, and as they practice their art they become more proficient. However some of the most powerful spells require days of meditation and ceremony.

Scholar Magic
Years and years of study have enabled those whom aren't naturally capable. This often requires ingredients and a device through which to channel this power. These are often staffs or wands. Their most powerful spells take days of ceremony and preparation to work.


And of course you could make your own.