This is just not what Constructed is about
Wild Mongrel is already a great creature, but when paired with double-strike effects like Double Cleave or Soul Fire, or madness cards like Basking Rootwalla or Reckless Wurm, it becomes one of the best cards in your deck
You get lifegain and card advantage based on the sacrificed creature's power, making it a versatile creature that can fit into many archetypes
That's a bit of an exaggeration - there are likely to be cards in the deck that we want to keep, but I almost assuredly want to pair Eulogist with a Bant deck
And the abilities that the network created itself, like Tromple (an amusing mangling of Trample) simply existed unexplained on some cards until it was illuminated by Adakar Vitionary: And of course, because MTG has so much flavor each of the five colors in MTG have their own style of play, most-used mechanics, naming principles, etc
It only costs one mana, and, for the cost of two mana and two life, players can activate Phyrexian Reclamation to return a creature from their graveyard to their hand