how can we get reverse to any point after we reach the end point using the animations?

Answer 1

animation:glow 10s ease-in-out infinite;
^ the infinite part might be what you're after

Answer 2

animation-direction: reverse; /* play in both direction alternatively / use with animation-iteration-count */
( to check if this is what your expect, and to study how to use it: https/developer.mozilla.org/en-US/docs/Web/CSS/animation-direction )