Enjoying Invoker build so far; I always play Crusader but I am glad to be back to a tankier, stand your ground build, instead of last season where most chars were just tanky enough to kite.
I haven't gotten a blood brother, akarat shield, traveler/compass or convention yet, (which isn't surprising considering its been live for all of two seconds) but the coolest part about a thorns build is there are already so many thorns items that you can make a crushing build until you min/max.
Right now I'm running a haste/on hit type build with spiker shield - obsidian ring cubed, gogok, wearing rorg to utilize sanguinary and wielding hack. Only ability different from the normal invoker build is I'm using provoke instead of law to do double dmg with thorns.
Farmed a bunch of keystones and ran up to 45 with no trouble; 45 got a bit more painful and I died twice, but i still beat the rift by more than half.
Although super fucking wield feeling to not give a shit about weapon dmg.