It's a red instant that costs four mana, and it requires the additional cost of discarding a card from your hand
In particular, I like the ones that are creatures since you want to keep a high density of creatures, like Kami of Whispered Hopes
With its dark fantasy artwork and eerie presence, Nightmare quickly became an iconic card, often appearing in core sets for years after its initial release
After all, these are just boring ol dime a dozen tokens that could be acquired anywhere else
Witness is mostly used to secure some redundancy on thinly stretched decks with roughly one answer each for a variety of things or as part of a creature focused combo deck
Midrange strategies like Jund barely blinked at pitching extra cards, while opponents often struggled to recover