Aura 'Cost' and 'Reservation%' difference.

I have been following poison srs builds from many players and finally found a good build that suited me and that is SadPanda's.

I noticed from the many shifts I made that the aura change from reservation to cost, and I don't like the cost since my mana comes from the energy shield and that thing doesn't deplete.

my passive skill tree, gems, items, jewels and basially everything follows the guide (except the boots, March of Legion) I am using, but I really can't figure out what the problem is.

I ask for your guidance and hope that this is a trivial problem that many asked before me. I just started the game two weeks ago and I don't know much of it.

auras don't have a mana cost unless supported by divine blessing support. what exactly are you asking?

My question is how to make auras a constant buff. tempest sheild does not go away after I activate it but the others have a specific time before they go away.

I guess you just answered my question :)

March of legion boots is where I added my auras and that explains it, thank you. I will change it now.