When a creep steps on the portal, it is transported to the other shard, only retaining its body and name. It will get a new ID and will have no Memory. You will have to set up a system to restore/initialize new memory for it.
This is gonna be very hard. Since claimers can only live for 600 ticks, and the place in Shard 2 or 1 (where the portals near me direct to) is basically fully occupied, so even if my claimer gets there, it will need to travel a long way to find a relatively good and safe spot. But I will try it. If it doesn't work, maybe I should respawn in Shard 2 first, and then travel to Shard 3
Thanks again for the help and encouragement.