Guild Wars 2

Every profession would have a rune only appliable to a back piece that would add a new effect to their profession skills. They would be soulbound on aquire and perhaps be purchases through karma, or if possible a Profession exclusive short story line that rewards them with it and are only availible to those level 70+. Some ideas for Profession skill runes could be:
-Thief steal interupts actions.
-Warrior profession skills heal for 10% damage done.
-Guardian Virtue of justice active adds 1 extra burn strike to allies. (Total of next 2 strikes burn)
-Elementalist attunement releases a torrent affecting foes within 400 units of them with that element upon switching. (Earth cripples, fire burns, water chills, lightning dazes. All durations last 2 seconds.) Cooldown 10 seconds.
-Necromancer when entering Death Shroud causes vulnerability to foes within 500 units for 3 seconds . 15 second cooldown.
-Engineer Using a toolbelt skill lowers all other cooldowns by 1 second. Excludes the skill itself.
-Mesmer Mind Wrack deals 5% more dmg if the target is under the effects of a condition.
-Ranger while your pet is downed, it gains a slow regeneration (2% max health per second). This takes longer than switching pets but its that 5 extra seconds that you could choose to wait out if the current pet selection is the one you need more.