"Herblore
- Concoct potions that will poison the beast / water supply / minions;
- Concoct potions that will boost your battle golem - different potions give different bonuses. This could be limited so bonuses that work well together can be used, but it shouldn't be possible to use all the boosts at any one time."
I think I like this one the most, but to develop your suggestion, I'd make the potions into a cauldron where NPC mages supply their magic powers from, dipping their wands or staffs into it and then damaging the beast. This could take away from the battle golem, but there needs to be more mechanics for it to be a boss:
1.) Dump Potions according to the beast's armor or combat style being used to supply power to the mages to damage the beast.
2.) Avoid incoming attacks with surge or avoid stuns with freedom and run back to the Cauldrons
3.) Maintain Cauldron Health but deal less damage doing so (temporarily) by dumping material rebuilding potions.
4.) Once a Cauldron is Destroyed, you could run to the next cauldron OR apply potions directly to Mages on time (some die before they even make it to the boss, so you'd have to watch your allies HP)
5.) The goal is to maintain cauldrons and battle mage's damage to the beast. You'll have different types of powerful mages on your team enter the fight (NPCs) to assist them on time to deal damage efficiently.
6.) Order Battle Mages to enter the field OR additional Cauldrons to be built. Select which mages come out when and why & select which cauldrons come out when and why.
7.) Splash a special potion directly on the boss when he gets ready for an instant kill mechanic but surge/escape/bladed-dive/barge out of the way of his secondary attack (the potion negates the insta-kill)
To make it pure skilling, you'd take away the combat danger, and replace it with failing to maintain cauldrons or support battle mages to kill the boss. Depletion of Cauldrons and Mages would result in a defeat.
5.8b XP