Black is one of the best colors for Lifegain, and cards like Exquisite Blood are the main reason as to why
Its a card that Im happy to have in my opening hand or to draw on turn 10, and anytime in between
If you cast one Zombie creature card from your graveyard and then have a new Gisa and Geralf come under your control in the same turn, you may cast another Zombie creature card from your graveyard that turn
Their model is best described as pay to not play as a lot of grind can be skipped by opening ones wallet, but as both games have fun mechanics (Duel Links even has another entire game and format within called Rush Duel), if you love them, you wont mind grinding them
However, theres a specific breakdown of each card type and how many to include because of their use in the game most decks include around 15 Pokemon cards, 30 Trainer cards, and 15 Energy cards
Example: This sample hand from a typical Grixis Deaths Shadow list doesnt want to wait on a cantrip