Hey U_K! What template/set of templates would be needed to make a hekatoncheires at classical myth power level? (i.e throwing mountains at people as a main tactic.)
I don't think it would necessarily be done via Templates. Throwing a Mountain is a Legendary [Strength] Action for a being with a certain strength score - I can't recall exactly off the top of my head but for argument's sake lets say Strength 40. I think Thor with his Belt (+6*) gives him Strength 40. Base 24 (Level 20 Barbarian), +10 (Divine Rank 5) = 34, +6 using the Belt.
*Strength 30 to non-immortals.
As regards the Hekatonkeres, you have to understand their role in the Titanomachy. The three Hekatonkeres were enough to swing the battle between Gods and Titans. So they have to be at least on par with Zeus = Challenge Rating 36. That gives them 160 Hit Dice...which in turn gives them a Multi-attack damage of average 96d8 (60%) to be split among its various attacks and no I would not give it 100 attacks just that it can attack all adjacent targets within reach and throw boulders at all targets within range. Maybe 3 attacks, some combination of 191 (32d10+15) melee slashing damage or 127 (32d6+15) reach = its space, ranged bludgeoning damage (range is its space x10). Its Legendary Reactions would deal 10 dice, escalating from d4, d6, d8, d10, d12 to d20* (tentacle grab, babbling confusion etc...up to some sort of whirlwind of stone movement as it churns through the ground for the bigger Legendary Reactions).
*Often 2d10 instead of the d20
So monsters do no necessarily need a template unless you are converting an existing monster (Giant Boar to Legendary Giant Boar, etc.). Of course we could have a 6d 'Super'-Hekatonkeres and then apply the Super template (the idealized form of that being in all timelines - third extension of the Paragon, Amidah chain) if we want the Hekatonkeres to be tossing Universes instead of just Mountains...but I am sure no one would be crazy enough to build something like that.
