Weird. Pretty much strictly better than Exploration. In a duel you will basically be playing an extra land every turn (more if they use land ramp), and in multiplayer it is all but broken. It is likely to empty your hand of lands by the time your second turn comes around. It might have been balanced at 4+ mana but this is just a monster. These are the kinds of cards that ruin magic for people that don't have swollen wallets. I tend to rate these cards very low due to their ability to make a mockery of such an otherwise fun and balanced game. In my book, Time Walk is a 0/5 and Rites of Flourishing is a 5/5.