Eren nodded in response to Argo's words.
Realizing that he himself was departing from Anfang, Eren understood there was no need to keep him tied to this world. Eren believed that, if fortune favored them, they would meet again in another world.
Argo had provided crucial assistance to Eren, greatly supporting Eren's version of the Lazarus Project. While, as a being with the soul fragment of a Demon Prince, Argo might view his actions as insignificant, Eren highly valued what he had done.
With this in mind, Eren resolved to repay Argo one day when he possessed the strength to do so.
"Aight. Time to yeet… but before I go… in this world of Anfang, this shall be my last gift to you, boss. Use… use it well."