Deadly is dot based, so best class for this set is stamina DK with 4 dots, usind duals/bow/2h. Dragonguard elite gives you up to 3213 crit (which is still less than Leviathan's constant crit) if you're repeately hitting target in the face or flanks, so its better for pve than pvp. Though if you want highest crit, use Yokeda (it gives up to 3666 crit), but you'll be locked to full melee range.