I'm pretty sure the front side is too powerful. Overrun is not a weak card, and this is already a higher power level on average (first strike makes it such that gang-blocking is very unlikely to kill your creatures, making this a one-sided board wipe if you fail to kill immediately). You probably won't be using random powerful creatures with this either, but prefer those with higher toughness, effectively making the buff even greater. I'd knock it down to +0/+2 and then it should be fine. Powerful, considering that this is a dual land unlike the zendikar rising ones, but fine.
We had a discussion about cards like these a while back. The challenge is that the spell side needs to be something not strong enough that you would be willing to put it in a deck of those colors by itself and the spell you have above would pretty much be a first pick GW card without the land side already.
If it didn't give the +0/+3 but everything else was the same, I could see this being more printable.
Both of you made a good point, so I'm changing the card some.
? - 4GW
Creatures you control gain Trample and First Strike until end of turn.
Creatures you control deal combat damage equal to their toughness this turn.
? enters the battlefield tapped.
tap symbol : Add G or W.
Truly wish I could come up with a location that felt right. I liked the Zendikar Rising name convention for the MDFC land cards. I'm not comfortable making up names, though. Probably let's say the land backside represents some kind of wide flat open space where people feel their spirits begin to well up... oh, hmm. Spirit Upwelling and... ah, no. I'll think of something eventually, maybe.
(something Prismari-flavored I think) 3UR
As an additional cost to cast this spell, discard X cards.
Copy target spell with mana value 2 or less X times. You may choose new targets for each of those copies.
Other side... yeah, you know.
edit: I'm doing a BG card and I feel like doing a deep cut. An Ulgrotha reference.
Veldrane's Desperate Hunt - 2BG
As an additional cost to cast Veldrane's Desperate Hunt, sacrifice any number of creatures.
Veldrane's Desperate Hunt deals X damage to any target and you gain X life, where X is the total power of the creatures sacrificed this way.
MDFC is less upside than the same effect on a sacrificing activation though (since you typically use both of them in the late game, losing your land-drop doesn't really matter, and a sacrificing activation can still be used after using it as a land)
I feel like the new designs could almost (but not quite) go on an activated ability that does not sacrifice the land (except the BG one), so they should be fine on MDFC
Veldrane's Desperate Hunt - 1BG
Target creature you control gets +4/-4 and gains Lifelink until end of turn.
That creature fights target creature you don’t control.
Veldrane's Hunting Lodge
Veldrane's Hunting Lodge enters the battlefield tapped.
, Pay 1 life: Add B or G.
This is an overly complicated way to say "sac a creature to destroy a creature"
Your creature would have to be an X/5 to even survive the toughness reduction (though it does still always gets to fight since it won't die from the -4 until state-based effects check after the spell resolves) and then it would have to survive the fight as well, so at that point it should just be:
As an additional cost to cast CARDNAME, sacrifice a creature.
Destroy target creature. You gain life equal to the sacrificed creature's power.