My partner Grall just made one of these; it's one of his nastiest decks, and I helped with the mana base and some mechanic decisions.
I like where you're going with this deck, and it's very different from where we went; I'll upload the decklist in a bit if you want to take a look. TOKENS!!!!!!!!!!
First thoughts:
Remove:
any token card that only creates 1 token a turn, or you waste Esix's ability and your own removal getting rid of it later.
Scute SwarmAwakening ZoneKhalni Garden Kessig Cagebreakers: too conditional
Hornet's Nest
Beast Within: it helps your opponent too much, unless you're planning on using it on your own creatures, which is unnecessary with how many tokens you can make.
Pongify: same
Curious Herd: too conditional
Sakashima for MirrorBox (one is a lot cheaper than the other mana and $$) and if you copy your own creature with a mass token creation spell and Esix, the original gets a massive boost to its stats. Or
consider Sakashima to be a win-con if you mass copy it instead of token production.
Skittering Invasion: mana cost is too high; switch for something like
Hangarback Walker which has multiple uses, but is more expensive
Avenger of Zendikar: I think it will be too difficult to pull off with the current land issue you're having -
consider putting it in the sideboard for later 'cause it's cool.
Consider adding in:
Instrument of the Bards as a creature tutor - it's clunky to work with but does its job multiple times before most people start to care about it
Or
Parallel ThoughtsFractal cards that make BIG boys that you can have Esix copy any other creature you want like
Body of Research which gives you a boy the size of your library
Tangled Islet: you can fetch for it
Rimewood Falls: same
Temple of Mystery: scry is always nice
Dreamroot CascadeLumbering Falls: a creature with hexproof to copy to make more lands, then creatures
Hadana's Climband whatever else you need to get to a bare minimum of 38 lands
You'll want to replace the removal and ramp, rather than just take it out. I'm also not sure that you're doing enough consistent draw to justify
Reliquary Tower.
Hope this was helpful more than not