I need to see things in context. I would never say. "Some people think that THE Tarot is evil". I would omit "the."
I would say "in terms of divination, some people prefer tarot, others prefer runes" (without "the").
When would I say "The" tarot?? Not quite sure. Only when I want to specify a particular type, e.g The tarot of Marseilles, The Soprafino Tarot. I would say The Tarot of the Witches, but I'm sure others would say Tarot of the Witches. Aaaargh!
The tarot developed in the 15th Century? No, I wouldn't say that, I'd say "Tarot cards developed in the 15th Century"