The title should actually be 'terianthropy', as it concerns beasts other than a wolf, but ah, whatever.
The following is heavily inspired by the Werewolf skill line - source:
https://en.uesp.net/wiki/Online:Werewolf
Ursanthropy skill line (werebear)
ult: werebear transformation (stam)
a gives major courage, damage causes minor cowardice, minor fracture
b +more life, stamina, magicka
skill 1: charge (stam)
a untargeted, on hit pushes and stuns, increases cost by 33% (stam)
b AoE stun, increases cost by 33% stam
skill 2: roar - single target (stam)
a AoE taunt
b AoE damage, no taunt
skill 3: steal life on L and H attacks for X seconds (mag)
a life stolen + 2 sec ult duration
b life and mana stolen + mag regen + 1sec
skill 4: harden fur (damage shield) (mag)
a stronger shield
b reflect % damage
skill 5: rejuvenating roar - self-heal HoT (stam)
a HoT + minor vitality
b AoE HoT
passive ursanthropy:
-take more damage from poison
-increase stam, armor, reflects % damage
– devour: restore health and stamina
– grants Minor toughness for 6 / 9 sec after feeding
– prolongs the form [edited]: by X sec after taking damage
– chance to cause bleed / stronger bleed dmg
– chance to stun for 1 sec when L and H attack [edited] --> when breaks free, roars to stun AoE
– chance to reflect % of dmg / [edited] increases amount of dmg blocked