Radha, Heart of Keld is yet another extremely interesting legendary creature from the new core set. While it may be tempting to make a Gruul stompy deck, like what you would do with Xenagos, it would just not be any fun. This card lends itself perfectly to a landfall deck.
It is not unheard of for commander decks to hit a point where players have 15 lands each. Thus this is an opportunity to experiment a little.
It is true that there are plenty of decent Gruul commanders who lend themselves to the landfall archetype. Omnath, Locust of Rage is one of them. So you might wonder why you would choose Radha. While it is true that Omnath has a much more impactful effect, Radha, Heart of Keld has the advantage in that it gives you mana fixing reliably as early as turn two. Radha’s first effect is great when you have few lands in hand, and it helps you get to your bombs faster. On top of that, who says that you can’t play Omnath as 1 of your 99?
Your game plan is as follows: get a bunch of lands on your field as soon as possible, get some landfall value, and knock your opponent out when they do not see it coming. How do you do this, you ask? Well, if there is something that green has, it’s ramp. With spells like Kodama’s Reach, Azusa, Lost but Seeking, Wayward Swordtooth, Cultivate, and Skyshroud Claim, you can build things up. You get the point. A combo that you will want to play is Scapeshift+Splendid Reclamation.
On top of that, there are a lot of cards that can make use of the land coming into the battlefield like Rampaging Baloths, Lotus Cobra, Tireless Tracker, and Avenger of Zendikar. All you need after that is some removal and some card draw. Voila, your Radha, Heart of Keld deck is complete.