1 - An image of Dr. Strange's original pilgrimage to the Ancient One's temple to learn the ways of magic. Dr. Strange is haughty and overconfident; the Ancient One is calm and serene.
CAPTION (THE ANCIENT ONE): "It is not a simple matter to take on an apprentice."
2 - Jump forward in time in Dr. Strange's training. Dr. Strange lies on the ground, having been overwhelmed in an attempt to cast a light spell. He looks disheartened and defeated. The Ancient One stands nearby, having successfully cast the same light spell, which burns brightly above their hands.
CAPTION (THE ANCIENT ONE): "It's not that a good student should never make mistakes."
3 - Jump forward in time to Dr. Strange being his own hero. He is in a similar position on the ground, but he has a small shield of light above his head, which blocks some negative energy being cast at him by Baron Mordo. Dr. Strange grits his teeth in determination.
CAPTION (THE ANCIENT ONE): "But that they have the strength to recover and learn from them."
4 - Jump forward in time again. Dr. Strange stands tall, casting a cascading wall of light towards Dormammu, who floats ahead in the darkness. This should be outside, at a distance where it's still clear who both characters are but also at a remove where the scale of what Dr. Strange is doing is also clear.
CAPTION (THE ANCIENT ONE): "Ideally, they will not only surpass the master."
5 - Shot of planet Earth from space. A huge halo of light surrounds the planet. Whether or not this is a leap forward in time is immaterial. To the side, an enormous, ghostly version of the Ancient One watches on, satisfaction on their face as they fade away.
CAPTION (THE ANCIENT ONE): "They'll also light the world long after we've faded away."