This has Cloudsplitter written all over it. While cloudsplitter will not be a BST best ws in 90% of situations, a Career BST knows that he will be suited for any situation.
Drops from Aht Urghan VW T1 mob Vanasarvik in Mount Z.
Vanasarvik is an Imp that uses the typical high level/NM Imp moves and (re)summons 4 Elder's Imps upon use of Bugle Call. All 5 mobs synchronize TP moves Grating and Stifling Tantara and Frenetic Rip. Both Tantaras are high damaging AoE moves that do around 500-600 damage to an Ochain PLD. Both are negated under Fanatic's Drink.