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Most builds posted here are designed to be used by the player at endgame (lv94+), and many are gear-dependent and will not perform properly until you put on that endgame gear. In many cases, players will level with builds entirely different than the endgame ones they eventually intend to spec into, either because leveling is easier/smoother that way or because the endgame build is so gear-dependant that leveling with the desired endgame build is not really possible.
While you could farm lower level versions of the Monster Infrequent amulet that makes the vitality Devastation build possible and use it during leveling, keep in mind as well that Devastation is a skill towards the end of the skill bar, so it’d take a while to even get a build up-and-running that plays similarly to the one posted here.
Instead, maybe take a look at
for Spellbinder leveling ideas.
The guides labelled “beginner guides” on the forum are generally pretty good at taking you through the leveling process and contain both skill and gear suggestions, the latter of which are typically formulated so that you can avoid having to rely much on RNG to get that gear.
Also keep in mind that if this is your first character, you may be at the mercy of RNG for a time (maybe a long-ish time) while you wait for the appropriate gear pieces and/or blueprints to drop that will allow you to complete the build.
As an aside, I decided to do a fresh start Spellbinder recently, and while I did something different (and somewhat less efficient) for leveling, I’ve found that something like
specifically the “Alternative build” setup by @ya1
has been a nice rough template to shoot for as an intermediate farming goal on my way to the final build— Krieg set is target-farmable, and Scion of the Screaming Veil, while not target-farmable, drops from Aetherwarped Totems at an increased frequency, so it gave me something fun to look forward to while Totem farming in Ultimate difficulty. (Mostly the proc on Scion weapon is really cool looking, so now I have something cool to look at while I get more gear.)