Could it be
LEADERSHIP?
I got to this just by following my nose in the first verse. The OP has written another riddle with this very answer though.
A relationship so justified
Many leaders consider their position as leader, and the relationship they consequently take to others, to be justified.
Sensitive in nature deemed classified
Some leaders hide away and make decisions behind the scenes, so their role could be seen as classified information.
Stained the world in all aspects
Certain leaders have made very bad decisions and left great stains on the world. Even today, Adolf Hitler's very name can be used as a synonym of evil.
Likely to start future prospects
On the other hand, some leaders have wonderful visions of the future and make great things possible.
Vandalism left still enduring
A similar reference to the 3rd line, perhaps: the wrecking decisions made by long-gone leaders still leave their marks on the world.
Physical marks keep alluring
Symbols of leadership, such as crowns, sceptres, and diamonds.
A timeless art made from bone
Not sure about this line.
In Rome a cephalopod you might own
A reference to Roman emperors maybe. I can't see how cephalopods come into it though.
Arch the enchanters wand
One which Edward would be fond
The blood runs with absolute
No matter if you are mute
This is probably a reference to some fictional work involving enchanters and a character named Edward. I haven't worked this verse out yet.