I hid under the stairs/crates and shot him thru the crates with black hammer and Gjallarhorn , it wasn't easy to shoot thru that little crack with gally without blowing myself up but I succeeded, then when he moved to far side I jumped up on crates and shot gallys at him...then had titan jump out pop bubble on the dock where Valus comes out and shoot rockets then retreat in to reload w/ weapons of light on...one guy stayed under stairs to revive just in case but it worked out fine...didn't consider it cheese at all..