I haven't done Glavoid on BLM brew but i would stick to Aero spells. If you have multiple pop sets might even want to aeroja then aeroga III aeroga II then single target as needed.
meh i've brewed a Ulhuadshi in Attohwa a while back... one nuke killed like 75% of its hp... glavoid shouldn't be any different. Just keep nuking until it dies... even if a nuke heals it you have 3 minutes... more then enough time.