Sergeant Damien ~ invoking will give you camo gloves, camo boots as well as dog-tags (these are not from an unplanned event, therefore RS gold they cannot be kept in a costume room). The Demonic Blade ~ after you have the plans and pieces from the seals, head to an anvil and bring 80 smithing, a mithril bar, the pieces, the plans, and obviously an Hammer. You can make the demonic sword by using one of the pieces of the anvil.
The blade shares the stats of a dragon 2-h however it is able to deal 250-500 damage against demons (and Zamorak). It also has a very high accuracy rating and the special ability to deal 50 poison damage for half the rate of p+. There's no way that the poison will not be inflicted. Although poison does not ensure that it will be able to harm other monsters, it does deal 10 damage. It's got the same special attack as a D 2-h, however it has a different animation, and it is able to stun monsters. To use this sword you must have 70 strength. But, it does not have cheap OSRS gold an attack. Even with its slow speed against demons, this sword is a good training weapon.