Priest · Shadow Magic · tier 2 · from level 15
Improved Shadow Word: Pain
+248 Shadow Word: Pain
2/2 · level 60 · per cast
Improved Shadow Word: Pain
Rank 2/2
Increases the duration of your Shadow Word: Pain spell by 6 sec.
Averages, counting crits and misses, for a level 60 Priest with a typical weapon and no other gear or buffs, against a target your level. Worked out from the game's own data, the same way as the Foresight addon.