Prophetic Guard/Aegis line

[Kelypto]

I'm new to Mystic (level 30) and I don't see where the Prophetic Guard/Aegis spell line is useful.  Maybe it is later on, but I have yet to have a situation I need it in.  Is this a rarely used spell?

[Sandain666]

This spell line is very useful in raids where you may face poison/disease AE attacks from mobs. Personally I don't use it too often when grouping or soloing. Maybe someone else has a unique use for this spell?

[Finora]

I use it when I know the mob that we were getting ready to fight casts noxious based spells.