I haven't bought any bricks* from the tower... and don't plan to do so really yet as I don't have the patience to wait for 10k
but I got the eido/wep brick last year from the $100 gacha thingy and LBed Mammon's gun.
Dazzling Gold Carbine FLB - Assault++/Rampart (Defender+Vigorous) and 2.9K max ATK.
I'm not really aiming towards any kind of grid for phantom weapons, it gives me a chance for a gun grid? if that's good? not sure... not too bothered about phantom weps tbh.