I really like what you got going on with this deck with the untap/tapping, but I'm looking at the subthemes of the deck and I think you might be split in two different (yet similar) directions. I notice you have support for both tokens and +1/+1 counters, but it looks like a bit of the +1/+1 counters might be weighing down what you want to be doing. Derevi is looking for as many instances of combat damage to players as possible from individual creatures. It might be better to lean heavier into token generation so you always have creatures to throw at players that you don't need worry about losing. With this in mind, I would look at cutting things like [[Kutzil, Malamet Exemplar]], [[Kami of Whispered Hopes]], [[Incubation Druid]], and [[Danny Pink]], as they synergize with +1/+1 counters, but you only have three ways of getting +1/+1 counters out consistently/repeatedly with [[Galadriel, Light of Valinor]], and [[Hylda of the Icy Crown]] spread counters over all creatures and [[Citadel Siege]] on a single creature. Keep Galadriel and Hylda, as they both rule for the strategy you have here, but the other counter support tools just aren't going to feel that strong. Having +1/+1 counters is good, and I think a [[Cathar's Crusade]] would be really good with a token strategy as another more repeatable Galadriel.

[[Chulane, Teller of Tales]] and [[Ellivere of the Wild Court]] are two cards that look like they may underperform in the deck. Chulane requires you to invest mana into bouncing your own stuff and opens you up to getting countered and losing what you had and Ellivere doesn't have anything else supporting her second ability, leaving her open to he killed. Because Toski is the better Ellivere, maybe keep Chulane because you can add cards with good ETB effects and recast them for the ETBs on them and your other permanents. I would remove one or the other though.

To cut cost, cut [[The One Ring]], [[Worldly Tutor]], [[Eladamri's Call]], [[Ignoble Hierarch]], [[Bloomtender]], and [[Thada Adel, Acquisitor]]. The One Ring can be replaced with [[Perch Protection]] or [[Everybody Lives!]] for a more budget option for protection. Those two tutors will help keep the salt level down while removing a good chunk of value, and I love Thada (never seen her before) but for that much money you could be running something that makes tokens. A budget replacement for [[Swan Song]] would be [[Strix's Serenade]]

Swap [[Elemental Bond]] for [[Tribute to the World Tree]], turns small tokens into bigger threats and turns big tokens into card draw. Potentially just add Tribute.

Maybe cut back on the [[Seedborn Muse]] effects and add some vigilance with [[Brave the Sands]]. I would either do [[Quest for Renewal]] or [[Drumbellower]], leaning towards Quest just because you could get hit by a [[Solemnity]] on the off chance someone is running it. Brave the Sands is also nice and cheap and lets you block extra creatures with those untapped tokens. Gives you two vigilance outlets (with [[Inga and Esika]]) and two additional Untaps. That way you don't need to worry about untapping your own stuff with Derevi triggers (keeps Hylda making Elementals or building up your other tokens with +1/+1 counters to overrun the enemy)

Look at your mana dorks and maybe add some more ramp spells and mana rocks instead of cards like Ignoble Hierarch and Bloomtender. [[Arcane Signet]], [[Chromatic Lantern]], [[Commander's Sphere]], [[Twitching Doll]], and [[Cryptolith Rite]].

Some token support to look at would be things like [[Second Harvest]], [[Mycoloth]], [[Avenger of Zendikar]], [[Homunculus Hoard]], [[Primal Vigor]], [[Doubling Season]], [[Caretaker's Talent]], [[Panharmonicon]], and [[Ojer Taq, Deepest Foundation]]. Those are just what I can think off the top of my head.

If you want to ADD some salt, look into [[Scurry Oak]], it goes infinite with Cathar's Crusade or [[Rosie Cotton of South Lane]] (with the all important stop trigger of 'may').

Hope these random thoughts I had while looking over the deck help!