Damage from Abydon's Hammer does not appear to be benefiting from critical damage, and may not be seeing any gains from apprentice's sneak attack. It is also applying Abydon's Power to all targets regardless of subtype (should be vessel only). Character using it is a 15th level coastal aumaua wizard with Two-Handed Style, Apprentice's Sneak Attack, and Weapon Focus: Soldier.
Save file and output log:
https://www.dropbox.com/s/6shi2nn953fb7wv/Save%20and%20log.zip?dl=0
edit: using patch 3.01