The card that the subgame winner puts onto the main-game battlefield doesn't have to come from the subgame battlefield
Pokmon's own Scarlet and Violet rarity update spells these out: "double rare cards are represented with two solid black stars," and "hyper rare cards will be represented with three shiny gold stars," while the older "solid black symbols for common, uncommon, and rare, circle, diamond, and star, will remain unchanged" (Pokemon.com)
[1] Except for the attack / defense monster, the only monster was the only one that was originally divided into 10 attack / defense by playing all the OCG and media mixes of Yu -Gi -Oh
Heartless Hidetsugu deals damage to each player equal to half that players life total, yourself included
Room for improvement The dataset used for training were official card art images used from ygoprodeck (dataset A) and not real life photos of cards in the wild / pictures of cards taken by a camera (dataset B)
These were Draft- and Limited-only sets with a strong focus on multiplayer gameplay