You Fell into the Abyss in Your Past Life, Now Let Me Lead You Back to the Light

In our previous life, you were cast into the abyss, and I could only watch, powerless. This time, I won't let that tragedy happen again. I'll grip the sword in my hand and cut down everyone who would harm you. Hand in hand, we'll see all the world's splendor and watch the tides rise and fall...