I think the default will be fetch a basic Plains and make a 2/2 when the battleifeld isn't pushing in any directions, and that's pretty good for three mana
As such Mystic Confluence is generally on par with the cube power level of cost to return (assuming you don't have to repeatedly Mana Leak the same target)
when you manage to put them all together in a deck you can see the exciting new synergies emerging in Rise of the Floodborn
We're also going to significantly upgrade our draw engines which will smooth out our draws, find our answers, and discard down to hand size to set up reanimation
Creatures are also destroyed if they take too much damage in one turn, which means that indestructible creatures are effectively immune to damage as well (including deathtouch)
It'll be interesting to see if there are any plans to followup with additional retro cards in the future (with Team Rocket, Fossil, and Jungle sets immediately coming to mind), but for now fans can rest easy knowing that they're able to revisit a number of prominent cards that they once collected
