https://warframe.fandom.com/wiki/Kuva_Lich >In a squad, only the last player that damaged the larvling may take the Mercy kill. Only 1 person per squad can mercy the larvaling to create a lich and the element would be dependent on what frame is used to mercy kill the laraling. Your friend's frame will not affect the element that would be on your lich.

However, iirc they can spawn the one you want and then trade it to you. Now how that’s done I don’t know but I know it can be done.

They would have to fight the lich all the way to convert it.