Disclaimer: I do not own X-men. If I did, Erik and Charles will be happily together doing sappy stuff.
It is not hard to understand Charles.
He is willing to let go rather than have Erik's spirit wilt under his love.
They always say the noblest form of love is letting go.
So Charles chooses to let Erik keep his pain and not wipe his memory
Because that Pain is Erik.
Charles is willing to be hurt.
Charles is willing to despair.
Charles is willing to let Erik make his mistakes and taste regret.
To understand how precious their love is.
(They never know how he felt when the coin sliced through his head, his heart. It was pain that etched into his very being akin to the engravings on the coin which cut through his mind. A little part of him dies every time he thinks about this. And he lies awake every night thinking about this, replaying this memory in his mind.
Sometimes he doesn't know if he's Charles anymore.
He doesn't know if he wants to be Charles.
Because Charles was not enough for Erik.)
So he waits.
And waited till the end of his life.
In the end, it was still Magneto. And his adversary Professor X.
Never Charles and Erik.
It is not difficult to understand Erik.
Under his iron facade, he is always and ever so protective of Charles.
During the mission against Shaw, he crouched over Charles so very protectively during the turbulence.
When faced with Charles's idealism, Erik will tell himself that it's okay.
Charles is only Charles because he has never tasted those hardships that will shatter a man's soul.
Erik's Charles should never abandon that innocence
Never be disillusioned.
So Erik is willing to continue to protect his Charles.
Erik will be the evil devil so that the innocent angel will never have his dreams broken.
No one shall know of Erik's sleepless nights where he lies awake in his regrets of how his angel faced harm at his hands.
(Erik did dream.
He promised to himself the moment he killed Shaw that it will be Charles and Erik forever.
But when the missiles were targeted at them, he knew that it was never meant to be.
They will forever be running, running from this unforgiving, unaccepting world.
He will have to be strong to protect Charles.
He will be strong so that Charles can live.
Even if it meant losing Charles.)
From that day on, there is only Magneto.
No more Erik,
Only Magneto.
When Charles died,
Nothing made sense anymore.
The world will burn.
For taking away his Charles.
The world will pay.
For Erik's pain.
When he lost his powers,
Erik was not sure how to feel.
Magneto was gone,
And Erik is left pondering over that unfinished game of chess.
After a while, the world just doesn't matter when Charles isn't here.
Nothing, not even vengeance matters anymore.
It was their 542 061th game, but Charles is no longer there.
Erik can only play over and over in his mind what Charles might have done.
Reality can't keep Erik alive, only Charles can.
So Erik waits.
He waits for that day where death claims him.
Where he will be able to meet Charles again,
the day when he can be alive again.
I promise my love, this time I won't let you go.