Roald relies slightly on fire piercing, and I have equipped Roald with the Sun Struck Horrors and Imperial Rifle, but I have to ask, should I give him some piercing, or focus purely on his stats? And which is more important for Roald? Strength or Vitality?
But in that case, is the imperial rifle still a good weapon for Roald? (I have an Emerald Death, but I use it and I'm too lazy to beat the hydra again)
I go for the balance, if my Sonny is weak in HP, I use Roald as a tank, if not, then as a damage dealer. It's generally better to be the toughest person in party, but if you can, just make the others tough so they can heal you and don't drop off that task because of the enemies.
I like strengthy Roald. All Royal set with a DS, maybe Colonel's Pants. If I make him a tank, he's pretty much useless, especially in PVP. He just sits around and stuns randomly while people focus on me and vera. I like him to do damage... usually.
In my experience the best gear for Roald is the secret police gear (there the ones with the red armor and the funny hats), and the DS sword that the mayor drops. He has good health and does decent damage consistently 1000-1200 damage, not much but certainly nothing to sneer at. I have never been dissatisfied with his performance in that gear.