Obsidian Armour Has No Negative Mage Bonus
Now most of the time, melee combat gear has a negative magic attack bonus. Which means casting spells in full melee armour is going to be super inaccurate. Well, obsidian armour actually has no negative magic attack bonus at all. They give the second highest in slot strength bonus with impairing your magic attack. I’d imagine this to be extremely helpful in hybrid or tribrid pking. Or possibly at things like barrows where you need that extra bit of defense in the downstairs area, but you don’t want to impair your magic attack. The full set does have a negative magic defense bonus, but that’s nowhere near as bad compared to things like the barrows sets or dragon armour.