What do I have to do to become an assassin, valkyrie, and zenmaster? Where do I get these special quests? Thanks in advance.

You get the assassin quest from Scanthril near the burnt house nw of Ishad N'ha.

To become a Valkyrie a FEMALE character must put the lich's heart into the black fire in Cet's Tomb.

To become a Zen Master you must collect all four tomes - fire, wind, water and earth.

Hope that helps!

Wyv