I am an xbox player as well and I noticed that Tenacious Concealment was bugged day 1 of hitting 70 and made a thread on here in the bug report sections. Never got any acknowledgement over it and have had to respec twice so i didnt have the 4th point in it. Once you do u lose stealth while taking damage and it also doesn't…
First off you don't want the level 60 artifact weapon the new level 70 artifact weapons are way better and to change the at-will bonus u just have to use the cubes of augmentation from wondrous bazaar. The old artifact weapon is obsolete when 70 because u get the better one from finishing spinward rise.