All melee attacks deal 27% additional Holy damage, but the Paladin loses health equal to 10% of the total damage inflicted. Lasts 30 min.
Unleashing this Seal's energy will judge an enemy, instantly causing [.36* MW + .25* SP + .16* AP] Holy damage at the cost of health equal to 33% of the damage caused.
Seal of the Martyr allowed a Paladin to deal a large amount of Holy damage with every strike, but had a backlash effect which would damage the Paladin. It was possible for Paladins to kill themselves when using Seal of the Martyr which probably lead to its removal from the game in patch 3.2.0.
The Seal is based on the melee mechanics for hit and crit.
The seal only scales with weapon damage, not spell damage. It therefore heavily favors melee-geared Paladins (mostly Retribution Paladins), rather than spelldamage-geared Paladins. Note that the Judgement does scale with spell damage.
This seal is counted as a second melee strike in terms of game mechanics, meaning that the damage it deals can miss, be dodged, be blocked, and be parried. Since it deals non-physical damage, it can also be partially resisted when used against mobs that are higher level than the player. It will NOT activate Judgement of Light and Judgement of Wisdom nor any other weapon proc (fiery, mongoose, life steal procs, etc).
When using a fast 2-hander, this seal deals more DPS than Seal of Command. Also, the fact that it can crit makes it shine in a raid situation since Vengeance is similar to a fury warrior's Flurry in terms of how it increases the paladin's DPS.
Seal of the Martyr's damage inflicted to the user is not capable of causing a Reckoning proc.
The Paladin Retribution talents Sanctified Seals, Vengeance, and Crusade all affect the damage dealt by this seal (prior to patch 2.1.2 there was a bug that would cause it to doubly affect the returned damage component of this seal, making the returned damage more than the 10% stated on this seal's tooltip).
In parses, the % crit may sometimes seem off. This is normally because of the backlash (self-damage), which cannot crit. Generally, in these cases you can double the posted crit rate to determine the actual crit rate.