yugioh speed duel deck GX: Midterm Paradox Yu-Gi-Oh! Mini Box Speed Duel Yu-Gi-Oh! Speed Duel GX: Duel

The mana discount it offers turns a pile of clunky creatures into a lethal Aggro deck

However, not every XYZ monster follows this design principle, as some cards can be summoned with a plethora of materials, and one of these powerful cards is Number 86: Heroic Champion - Rhongomyniad

A Bao A Qu, the Lightless Shadow X DARK Link 4 [ Fiend / LinkEffect ] ATK 2800 DEF - 2+ monsters, including a Fiend monster During the Main Phase (Quick Effect): You can discard 1 card, then activate 1 of these effects

Tezzeret the Seeker is a huge value engine in its deck, getting multiple activations on its mana-generating artifacts and tutoring up response after response to the Elspeth white weenies deck