Main Deck monster, then use its effect to summon itself
Getting plenty of play will probably have boosted its market value at least a little, but ultimately it's the low supply, inherent to any prize card, that has made Diablosis so expensive
It can also be used for combos because it can also destroy cards of Whether the ritual to be used is the main house that can be searched with black steel or an easy-to-use high grade, if it is naturally incorporated into the Red-Eyes Deck, the main house that supports black steel, and if it is used as one of the ritual decks, Senju and Manju should also be included
For the players using these poisonous cards, I imagine its quite fun
And while, as always, there are exceptions to these rules, hopefully they give you a great baseline to start from