Usage of this ability will produce an amount of enmity comparable to that of a Provoke.
While this ability is in effect the amount of enmity generated by other abilites, such as spells or Shield Bash is increased. Research suggests that the total enmity increase while Sentinel is active is equivalent to +100 [1], the maximum amount of additional enmity possible [2].
Guardian can enhance Sentinel to reduce natural enmity loss while active.
When this ability is activated the user receives a 90% damage reduction. This steadily decays to 40% damage reduction at the end of the duration.
Valor Leggings, when used in conjunction with Sentinel, give an extra 10% damage reduction, resulting in 100% damage reduction when the ability is used. This steadily decays to 50% damage reduction at the end of the duration.
When combined with equipment that reduces physical damage, the damage reduction from the equipment is applied separately. (i.e. while Sentinel is active and you have an Earth Staff on, if you are hit by 1000 Needles, it will be reduced by 90% to 100 Damage, then the remaining damage would be reduced by an additional 20% bringing the total damage to 80.)