Players loved him so much, he made frequent appearances in later titles as well, perhaps most memorably in Final Fantasy XII where he wields replica swords of main characters from other Final Fantasy titles
When Yu-Gi-Oh came out and for the first decade or so after it was released, I do think it was probably the superior game
For example, if you put Null Profusion (an enchantment that says your maximum hand size is two) onto the battlefield and then put Spellbook onto the battlefield, you'll have no maximum hand size
If you gain Life Points by this, you can choose any number of Blue Medicine in your Graveyard and add them to your hand.
The Universes Beyond line of cards is set to feature many more outside franchises in the future, including The Lord Of The Rings and The Walking Dead, but Warhammer is a surprisingly easy fit, since it is already filled with role-playing stats and a passionate fanbase that shouldnt have any trouble adapting to the rules of the card game