Devotion for demolitionist. Need your advice

[Klim]

What better to spend points in devotion for demolitionist class?

[Aelies von Saladir]

Depends on how you're going to build that demolitionist.
But generally, I'd say you should aim for one or two 3rd tier constellations, they are awesome.
As demolitionists typically deal fire damage, unless you're building a very atypical demo, Ulzuin's Torch or, if you're investing heavily on skills with Lightning damage, Elemental Seeker, would be a fine constellation to go for if you're using devotion to complement your offensive. On your way there, just choose the first and second tier that grant you the affinity points you need as well as useful bonuses. For defensive, Tree of Life is useful for every character in evry situation. Going for it naturally let you have other very nice defensive constellations like Turtle, Dryad and Ulo.