Nissa, Casual-to-High-Power EDH (EDH / Commander)

Mono-green Commander deck I'm creating with Nissa, Resurgent Animist at the helm.

I am tinkering around with having two different deck builds for this commander: one for fun/casual games, the other for higher level games (I wouldn't call it cEDH since I have no interest in spending hundreds/thousands of dollars on fast mana rocks and expensive lands - I opened a Mana Crypt in a pack that would go into the high power deck, but that's about it).

The deck you see above is the more casual deck build (subject to change as I add/remove things that I feel would flow better, be more fun, and be more consistent inclosing out games); the idea is to get Nissa out and trigger her abilities as often as possible for extra ramp and card draw. Most of the creatures in the deck are either elves or elementals, which Nissa pulls from your library every time her second ability is triggered.

Step 1: Ramp. Step 2: Play big, stompy creatures. Step 3: Buff them up with things like Overwhelming Stampede. 4: Turn 'em sideways. Remind me to add in Pathbreaker Ibex and remove something less useful.

To make this deck more high-powered, simply remove all elves and elementals from the deck except for: Ashaya, Soul of the Wild + Quirion Ranger + Beast Whisperer (perhaps leaving in exceptions such as Fierce Empath that enable you to tutor for other useful cards like Kamahl, Fist of Krosa or Kodama of the East Tree, though FE is not necessary to include).

There will of course be other cards to remove/add in (I will make a second decklist eventually and link it here), but the main thing is to have these three cards as the only possible targets for Nissa's ability.

Within three triggers of Nissa's second ability (since she only targets elves and elementals, she essentially becomes a tutor if you only have the three mentioned above), you will have all three cards necessary for a short and sweet win-con. Ashaya makes all non-token creatures Forests in addition to their other types; tap Nissa to produce 1G; use Quirion Ranger's ability to return itself to your hand, and untap Nissa; use the 1G to re-play Quirion Ranger, which Nissa sees as a land and creates an additional 1G as QR enters.

Continue this process to net 1G every time, and in turn produce infinite green mana. With Beast Whisperer out on the battlefield, you can draw and play your entire deck. If you have cards like Surrak and Goreclaw or Concordant Crossroads, you can give them haste, trample (Garruk's Uprising, Overwhelming Stampede, Pathbreaker Ibex, etc.) and buff them up to swing for massive damage and likely kill the board in one turn.

Alternatively, with infinite mana you can also use Temur Sabertooth + Eternal Witness + Infectious Bite to create inifinite poison counters for each of your opponents, which will get you the win without ever having to go to combat (Emergence Zone can be used to do this at instant speed).

As noted before I will be tinkering with both of these builds to determine what would be the best fit for the casual side and higher power side. If you have any questions, concerns, or ideas on how to improve the deck, please feel free to leave a comment; I would love to hear your thoughts and discuss further.