Epic Lifegain combo

This land enters tapped. When this land enters, return a land you control to its owner's hand. : Add .

You gain X life if was spent to cast this spell and X life if was spent to cast this spell. (Do both if was spent.)

If you tap a permanent for mana, it produces twice as much of that mana instead.

Whenever a player taps a Mountain, Forest, or Plains for mana, that player adds one mana of any type that land produced.