I couldn't finish 'em. Looks like this's gonna get complicated.
It is best to keep Zack's distance from both beasts, and try to land some critical hits from their behind. The beasts have a deadly swinging axe and they can surprise Zack with backhand slaps. The player can guard whenever they raise their hand, or dodge if possible. It is best to to focus on one of the Vajradhara at a time. This may be difficult, but after one the giants fall, the battle will be easier. Magic attacks deal more damage than physical attacks.
Occasionally they will attack Zack with their synchronized Twin Tomahawk attack, which is unavoidable.
Vajradhara is the ultimate primordial Buddha, or Adi Buddha, according to the Gelug and Kagyu schools of Tibetan Buddhism. Achieving the 'state of Vajradhara' is synonymous with complete realisation.