[Bug/Exploit]Tempest of Set bugged feat.
To make it short, it seems that if you put 3 points in the feat "Presence of Mind" under the General tree (removes 20% casting time on certain heals per point spent),
your Life of Set healing spell becomes instant (though it should only have been 60% faster), but when you put the fourth point in "Presence of Mind" it's no longer instant, it has the cast time it's supposed to have (80% reduced).
I'm not sure if the other healing spells are also faster than they should at the third rank in 'Presence of Mind',
but I figure you could save a feat point or two, since you almost always use Life of Set more than the other healing spells