Simple sloppy answer picking bits out of the cards because lol lore. First curse is the actual gun that was used by Ward when he killed Yor. It was the gun passed around, despite being TLW's cards, since they were telling not of TLW itself, but how it got that name. The guns (TFC/TLW) look identical except for the color. We have all known since vanilla that the Golden Gun super is TLW, and it even states in the card how the "Fire ran through his arm into his cannon" and fired those legendary three shots. Get this: First Curse was "lost to fire." When Ward channelled the light into it, telling Yor "Yours, not mine" to the remark about being an end, the First Curse he was holding was "Lost to fire" (his solar light) and that final shot became his "Last Word". There begins the TLW legacy, explains the absence and mysterious destruction of TFC, and the origin of Golden Gun, in a kinda sorta lore friendly way. Don't care if it's accurate or not, but makes a hell of a lot more sense to me than the spinfoil hat conspiracy theories I see all the time.