How many Black Knights (Black Wings Generals) are there really?

True. But light is very hard to turn to darkness. Where there is light there is also darkness. Mikhail's loyalty was most likely the very flaw that led him to his downfall.

Poetic bullshit.
Darkness is an absence of light.

Source doesn't mean jack s'hit. We travel to the past and completely change the past. Those storylines are now nothing.

That's yet to be seen. We don't know how time travel works in Maplestory yet.

Freed is the one who hides Mir's egg, moments before he dies. He then returns to Afrien where he finally dies, being unaffected by the spell of the Black Mage. No adventurer involve.

Source? Mercedes & Evan Storyline.

Where in the Evan storyline does it say Freed hid the egg?
As has been pointed out, that would be quite a back-and-forth trip for someone who's dying.