This looks like a lot of fun. I like
pounce as a better choice, but maybe 4 is too much? You have a solid core plan with
hadana's climb and the counters.
Have you considered swapping out
Marwyn, the nurturer x2 and 1
pounce for 3x
Song of Freyalise? Marwyn is great if you can spit out a lot of elves, but
song of Freyalise should be more consistent to ramp, plus nice payoff if you need to start with smaller creatures - really big late game.
SereneTsunami killed me today with carnage tyrants and something like your build. They are good, I can attest. The tyrants are especially good when your opponent has already used most of their removal on other threats. Playing this on curve, no mana cheating even - that's bad enough.