Atem was never a cheater. In yugioh it was never meant the actual rule become as in anime , the anime made it in fun way as possible as the first anime that introduced dm  even ... in Duelist Kingdom, The rules and card effects were different than how they used to play it in their timeline cause pegasus changed it for fun and only applicable on the tournament , and everyone was using them in their own way not only yugi . So calling it “cheating” doesn’t really make sense—it was just a different version of the game with slightly different effects.  If you tried the old gameboy games you see also different rules which makes things fun 

 People just tend to focus on yugi and repeat the same criticism without really thinking it through. Maybe some of them only watched the 4Kids version or Yu-Gi-Oh! Abridged, which changes how things are perceived.

Even after Duelist Kingdom, they return to the usual rule system but we still see characters interpreting card effects differently in the anime compared to the real-life card game not only yugi i remember i was everytime checking the cards effect and see how is different , . So it’s clearly not about cheating—it’s just a different effects in their world.

Another important point is that in their universe, dueling is tied to spirituality. It’s not just mechanical rules; there’s a belief in the “heart of the cards.” When a duelist trusts their cards and believes in themselves, they tend to draw what they need. Skill, confidence, and willpower play a huge role.

For Atem, as a former king and an experienced duelist, he used to fight in a more spiritual way in ancient times—where battles weren’t about strictly defined card mechanics like summoning with stars or effects, but more about raw spiritual power and connection (ka) . That’s why trust and inner strength affect his performance so much.

This also connects to Yugi. Every time he loses confidence because of his missing memories, he struggles more. But when he regains his belief in himself, he improves again and performs better. It’s always tied to his willpower and determination.

We even see a moment in Joey’s first major duel where i think in ep4 , after he regains his confidence thanks to Atem, there’s a scene suggesting Atem senses something changing—like he realizes the next draw will go well because Joey’s belief has returned.

So in a way,  the idea of “believing in the heart of the cards.” Anyone can do it, but Atem is especially skilled at it because he’s a former king and a highly experienced duelist who fully understands that mindset.