Crypt costs zero to cast and immediately generates two mana, which recurs on every turn
Turnabout Turnabout is an easily broken combo card often seen alongside High Tide, though other mana doublers like Heartbeat of Spring and Mirari's Wake offer similar power
And then you can tap and shoot something for a damage as well, and layer damage onto creatures from other source, be a threat to small fry, and otherwise be involved with playing Magic
If you control three or more treasure (thats the bounty you get from being a good hunter), youll turn it into Yiazmat, Ultimate Mark, a powerful 5/6 with upside
Use efficient removal I feel bad saying something so obvious, but in a metagame dominated by Decay and Lilly, as well as decks that don't want to interact at all, Infect has a huge edge