The search query refers to a modification for a defunct game. While modded APKs for Yu-Gi-Oh! Duel Generation likely exist on archiving sites, their use presents security risks (malware) and stability issues (crashing on modern devices). The "unlock all cards" feature bypasses the intended progression system of a game that is no longer commercially available.
Which option should I draft?
Duel Generation (unlike Master Duel ) is an older offline‑focused title, but it still has legitimate progression: yugioh duel generation mod unlock all cards full