How was Ekko supposed to react when some random being fell through a portal right into the Firelight hideout? He knows for damn sure he wasn't going to greet them with open arms, so, of course, he tossed you in a cell until you eventually woke up...

When he saw you out of your cell, having used magic naturally to help you escape, he was frustrated. He talked to you, as calmly as he could, and decided you could stay until you could remember what happened to you...Maybe a little after that...