Bork uses Melee-Bassed attacks and can hit high. But Bork can also drain prayer "Soulspit". But don't be alarmed, they're not aggressive, therefore you have to attack them first before they attack you.
Bork can be found in two places, such as Sponsor Zone, also known as Ownercape or Ownercape Zone (you must be a sponsor) and by using the Boss Teleport System.
A big recommendation to kill Bork, is to use prayer "Soulspit" (prayer level 92 or higher recommended) and to wear White Glass Wings in order to keep your prayer at max. You also want a fast hitting weapon, such as Ice katanaor an Assault rifle. As for armor, Dragonbone Melee armor, Dragonbone (U), Flame Pernix, or Wolverine Torva would be your best bet. Other recommendation is to bring prayer potions and food. The best food to bring is Shark or Rocktail.