Story suggestions (mostly warhammer 40k)

Crossover with DxD

I own nothing and this is a not very kind suggestion

Grey knights dreadnaught is locked in a sleeping animation after he appears in a warp dammed dimension in the familiar forest. Issei try's to make the gray knight become his servant and he succeeded but he isn't bonded by will and has this dimensions God Emperor who while weak can support a devoted knight fighting in his name. This in turn causes the familiar contract to be broken cause a foreign power interfered. The knight once briefed on the history and enemy's decided to go on a crusade against all aggressors of mankind with the emperor guiding him from the shadows slowly spreading his might and power in both scientific fields and spiritual cults raising a base of power for his valiant knight in gray armour. I don't know how exactly you could turn this into an interesting story unless you make it a world builder with the army's of hell and heaven fighting this new power or a simple one-shot destroying HSDXD cause screw them.

Also if someone does take my idea and uses it but would like my advice on how I saw it in my head just ask me I'll attempt to assist in any way I can.