Allosaurus Shepherd makes sure our spells can't be countered by pesky blue players (or anyone for that matter). Furthermore, we have the option to sink 6 mana into it and turn all of our elves into Dinosaurs with base power and toughness 5/5. The nice thing is that this ability doesn't take anything away from our elves; they are still elves which means they still work with all of our elf synergies and they retain their abilties. This is objectively an upgrade and a decent way to power up our board if we want to go for a big combat damage push.
Boreal Druid is a simple mana dork that only taps for colorless but it is a 1-mana elf body that makes itself useful after it hits the field. Mana is still mana even if it's not colored.
Elvish Mystic, Fyndhorn Elves and Llanowar Elves are all functionally the same card. They are 1 CMC mana dorks that tap for and are all Elves. What more could we want?
Elves of Deep Shadow is another mana dork but this one taps for .
Heritage Druid can turn our elves into mana dorks by allowing us to tap any 3 of them to produce 3 green mana at instant speed. We'll be generating a lot of 1/1 Elf Warrior tokens in this deck so being able to tap them for mana makes Heritage Druid very useful.
Joraga Warcaller is a scalable elf lord. By that I mean we can cast it for 3 mana and it'll give our elves a +1/+1 buff just like any other 3-mana lord (such as Elvish Champion or Elvish Archdruid), however thanks to its kicker cost we have the option of casting it for 5 mana, or 7 mana or even more, in which case it will be providing an even bigger buff to our elves. This is a great elf at any stage of the game because we can use it to boost our elves early if we draw it early or we can sink a ton of mana into it late game and make our elf army even bigger.
Elvish Warmaster produces a 1/1 Elf token whenever we play another Elf (once per turn), so it's adding more elves to our elven army which is exactly what we want. He also has an activated ability that gives our elves +2/+2 and Deathtouch. Since it can be used multiple times, this is a good mana sink option if we have nothing else to do with all that mana.
Fauna Shaman lets us exchange a creature card from our hand for a new one from our deck. This is a great way to find one of our finishers if we're ready to end the game. Furthermore, it is an Elf so it works with all of our main synergies.
Priest of Titania can tap for a number of green mana equivalent to the number of Elves we control. At worst, even if she's the only one on our board, she can at least still produce 1 green. The ceiling, however, is insane considering how good this deck is at flooding the board with Elves.
Gala Greeters is a very versatile card because it lets us gain life, create a Treasure or buff itself whenever we play a creature. Sure, each of these effects can only be used up to once per turn, but we have so many ways to generate mana and tokens that we can very easily trigger Gala Greeters three times and get maximum efficiency out of it.
Leaf-Crowned Visionary is a fantastic elf lord because it's cheap to cast and also gives us the option to pay an additional each time we cast an elf to draw a card. A great card for the early game to give Lathril a power boost for more token generation and scales into the late game when we have a ton of spare mana and can just use it to pay a little tax on our elf spells to draw cards and keep our hand full.
Circle of Dreams Druid is literally a Gaea's Cradle on a stick. It taps for for each creature we control. At worst, it will at least be producing 1 green mana for itself.
Elvish Archdruid is basically another Gaea's Cradle in this deck, considering a majority of the creature's we'll be playing are elves. Furthermore, it gives them all a +1/+1 buff.
Elvish Champion also gives our elves +1/+1 but also gives them Forestwalk. So if anyone at the table is playing green, they're in trouble because our elves will be unblockable when swinging into them. That means Lathril, Blade of the Elves can safely trigger her ability. We also have Yavimaya, Cradle of Growth which can turn all lands into Forests so nobody will be safe regardless of what colors they're playing.
Imperious Perfect is another elf lord that provides them all with +1/+1 but this one has an activitated ability that can create an elf token. That's essentially another 2 power on board assuming we don't have any other lords or anthems and is a useful mana sink if we have nothing else to do.
Ezuri, Renegade Leader gives us the ability to Regenerate our elves for the cost of just . He also has an Overrun effect for our elves that we can activate multiple times if we have the mana for it. A great way to end games if our board is big enough and we have the mana to pump them multiple times.
Marwyn, the Nurturer buffs itself with a +1/+1 counter for each elf that ETB's. Then, it can tap for a number of equal to its power. So the stronger it gets, the more mana it generates.
Rishkar, Peema Renegade lets us distribute two +1/+1 counters on any number of creatures when it ETB's. Most of the time, we'll be putting a counter on him and the other on another creature. Then, Rishkar turns each of our creatures with a +1/+1 counter into a green-producing mana dork.
Farhaven Elf gets any basic land out of our deck and onto the battlefield. Just a simple elf body that ramps us and thins out the deck at the same time.
Wood Elves does sort of the same thing except it can only search for a Forest. However, the land can enter untapped, and it doesn't say "basic Forest", meaning we can grab Woodland Chasm and Overgrown Tomb if we want to, along with our Snow-Covered Forests obviously.
Timberwatch Elf can buff one our creatures' power and toughness equal to the number of elves we have. We can swing with Lathril and if she's unblocked, we can tap Timberwatch Elf at instant speed to give her a massive buff and generate even more tokens after damage has been dealt.
Realmwalker has Changeling so it counts as an Elf and benefits from all of our elf synergies no matter where it is (deck, graveyard, field, etc.). When we play this card, we should declare Elves so that as long as we control Realmwalker, we can cast Elves off the top of our deck. This is a great way to dig and take advantage of all of the elves we're playing. It sort of functions as card draw so long as the top card is an Elf and we're ready to cast it.
Glissa Sunslayer is a very versatile card because she gives us three options to choose from when she connects with combat damage. She can draw us a card, destroy an enchantment or remove three counters from target permanent. Most of the time we'll go for the card draw but it's nice to be able to remove an annoying enchantment or remove +1/+1 counters or Loyalty counters or whatever kind of counters we want. On top of all of that, she has First Strike and Deathtouch so she's pretty scary to block, making it all the more likely that she'll get through and deal combat damage to an opponent. And even if they do all have blockers, we have Rogue's Passage and Shizo, Death's Storehouse to make her more evasive if necessary.
Skemfar Shadowsage gives us two options when it ETB's: we can either make every opponent lose life equal the number of elves we control, or we can gain life equal to the number of elves we control. So it's either a better Shaman of the Pack or it's an immediate Wellwisher trigger. Versatility is the name of the game here.
Beast Whisperer lets us draw a card whenever we cast a creature spell. The nice thing is that even if it gets countered, we still get the card draw because we at least cast the spell.
Primeval Herald ramps us by getting a land out of our deck immediately when it ETBs but also whenever it attacks. It also starts with a formidable 3/1 body with Trample and in this deck will only get stronger thanks to all the lords, +1/+1 counter placement and other buffing effects we're running.
Canopy Tactician gives all of our elves +1/+1 and it can tap itself to produce 3 green mana.
Wirewood Channeler is a sort of back-up copy of Elvish Archdruid as it makes mana equal to the number of elves we control.
Nullmage Shepherd lets us tap any 4 creatures at instant speed to destroy any artifact or enchantment. Just some useful utility we can take advantage of in a deck packed full of creatures and ways to create creature tokens.
Seedborn Muse is mainly in here because it's a sort of win-con with Lathril, Blade of the Elves. If we manage to get 10 elves alongside Lathril and Seedborn Muse, we can use Lathril's ability to drain everyone for 10 life and pass. Then, the Muse untaps all of our stuff on every player's turn so we can activate Lathril again. Assuming no one has a way to stop it, we can drain out the table in 4 people's turns. It's not super reliable and there are better win-cons but it's something worth mentioning. Even without Lathril, Seedborn Muse is just a good card because it lets us keep mana up at all times.
Ruthless Winnower forces everyone to sacrifice a non-elf creature on each of their upkeeps. Not a huge problem for us playing an elf tribal deck but odds are it will be an issue for everyone else. It also gets around Indestructible and Hexproof effects because it forces the owner to sacrifice.
Soul of the Harvest has a sizable 6/6 body with Trample, making it a good attacker but its real value is that it draws us a card whenever a non-token creature ETB's under our control.
Wolverine Riders creates a 1/1 elf token on EACH upkeep (not just ours) and whenever we play an elf, we gain life equal to its toughness. So it helps us accelerate our board presence and gains us life from a tribe synergy that our deck is literally built on. Can't ask for much more.
Regal Force is a great way to refuel our hand because having so many cheap creatures and lots of mana means we can run dry pretty quickly. Regal Force draws us a card for each green creature we control when it ETB's, giving us more options and more plays to make.
Craterhoof Behemoth is just a good old reliable finisher in Green. This deck does everything the Hoof wants, it produces a lot of creatures and goes wide, so when Hoof ETB's, the whole squad gets a massive buff and Trample until end of turn. This is a reliable way to end games that have overstayed their welcome.