I would like to know how War/Martial Magick works if there is as such? It would be mainly centred around overpowering obstacles or enemies with wit, strength and force of will. If so then this could be the field I'm currently strongest in.

Wraith orbs might use a form of magick based off wraiths and their energies to some degree in order to empower those qualities such as empowering your ability to outwit 'enemies', Wraiths themselves might be spirits aligned with martial magick if there is as such.

In general however what can it be used for at most and is it very effective if you need all other things done? Such as destroying obstacles(Would depend on what kind) via say the will of 'conquest'.

You might want to track down Charles Odinfotce and his shop. It sounds like a Soul Sword is something you'd be interested in pursuing.