In the first issue it introduces Skaar as a child and shows him growing up with these little bug/alien things, eating things, living the life of a savage. Then it introduces Axeman Bone, a barbarian leader who has become the main power on Sakaar since Crown City was destroyed at the end of PH. Then it shows Skaar fully grown and ready to kick ass.
Issue two shows Skaar battling Axeman's army and eventually kicking his ass. Then it introduces Princess Omaka, a pink chick who is an heir to the throne of Crown City with robot arms. She ends up meeting up with Skaar at the end of the issue.
Issue three has Skaar teaming up with Omaka and they battle Axeman's army, dragons, and a bunch of Wildebots. By the end they decide (with the help of Old Sam, Skaar's friend who has helped him grow and learn) to go to the prophet rock so Skaar can obtain the same old power that his mother had.
Issue for shows them going to prophet rock, they battle a bunch or monsters on the way there, they get there only to find that what Old Sam intended to find was taken by the Wildebots, and then a Shadow Priest begins battle with Skaar and he is surprisingly powerful. The fight will be shown in issue five.