Casting multiple cheap cards early and then making everyone shuffle their hands and graveyards into their libraries and draw a fresh grip can be very disruptive to anyone whose early turns were relying on specific cards in their opening hand
Black is one of the best colors for Lifegain, and cards like Exquisite Blood are the main reason as to why
4 Water Energy: 2009 Unnumbered POP Promo (Promo) $11.89 Subtle Color The competition is heating up now, with this 2009 POP Promo almost doubling the price of the Paldea Evolved Hyper Rare, setting an impressive standard for the rest of the most valuable Basic Water Energy cards to follow
It also acts as a Dragon Blood, putting a counter onto a creature without needing to blow anything around to do so
So, up to you how much that matters
The discard effect is a reasonable failsafe, though discard spells arent at their best in Commander to begin with