First things first! Each mastery ability has at least 2 effects and usually these are complimentary. So even if the effects themselves are not incredibly significant, the combined total effect may be a bit more powerful than you initially realize. Mastery Abilities(overview): Inspire -> Bonus SDI, DI, and HCI The HCI increase means the subject hits more often. The DI will be a small bonus to base damage. SDI in PvM has no Cap so this is a boon to all PvM casters. ---> I dont find this too great for career PvPers with money artifacts and crazy suits, but for my characters which aren't able to Max out all this on their suits it does help. I find my dismounter misses A helluva lot less when he's buffed with inspire. Invigorate -> Bonus to All Stats, HP, Healing every 4 seconds. Strength Bonus ties directly in to melee damage and Int ties directly in to Spell damage. Dex buffs stamina which affects swing speed. And who wouldnt like an extra 20 HP. (Not to mention the extra Healing every 4 seconds is like +30-50 HP Regen). Resilience: Bonus to all regens, Poison Resistance, Curse Duration Reduction The regen means more mana for casters, more stamina for fighters and a nice almost 1hp per second regen rate. Quicker curing of poison, faster removal of bleed (for those without healing) less paralysis duration, corpse skin, evil omen, blood oath etc. Preservance -> DCI and Damage Reduction Not only does anyone under the effect get hit Less often, they also get hit for less when they get hit. (For all the pets and party members who can't ride swampies) Or if you want to take it further, This also stacks with the swampie damage reduction) Despair: Physical damage 20-60 , - a whole bunch of strength. So the target is doing less damage from their melee hits, has a lower hit point cap, (PvP armor falling off is sometimes a nice bonus), And dealing fireball to ebolt damage every 2 seconds and only having to stop to initiate the casting and then just keep them in range. (This is fun because once initiated it is not line of sight so if they run into a house, or hide they still continue to take damage as long as they are in range) Tribulation: 20-60%Bonus damage to target in addition to up to 32% SDI penalty and HCI Penalty So target is hitting less and their spells do less damage, and the damage they take is significantly increased.