I've been trying to find the right balance in my Lathril build as well.

Cards I think are cuttable here: Just Beaters - You are looking to flood the board with elves and pump up Lathril to make more elves. Traditional beater type creatures don't do much for you here so you can probably lose cards like Heedless One , Abomination of Llanowar and Elvish Vanguard . These cards don't do anything for you other than get big and swing which is counter productive to you strat.

Big Mana Producers - You want to flood the board early and elves in general don't have high CMC so you can probably lose some of the higher cmc mana dorks like Wirewood Channeler , Selvala, Heart of the Wilds , Joraga Treespeaker and Incubation Druid .

Other - Unless you plan on a lifegain subtheme you can cut Nissa Revane . I can't run Coat of Arms in my group because there are a lot of other tribal decks that also benefit from it. Higher mana elves like Eyeblight Cullers and Exquisite Huntmaster and Nath of the Gilt-Leaf are all cards I would consider cutting to bring down the average CMC.

Obviously just my opinions, I don't know if you have pet cards or what your plaugroup looks like just thought I could share my line of thinking!

Just want to say, I don't see the point of Bloom Tender in this deck. 2 mana, gain 2 mana maximum.

Typically, in 3-5 color you want to run Bloom Tender. That way you are making 1+ more mana than her CMC.

I will take a much deeper look at the deck when i get home from work.

You might like these:

Ivy Lane Denizen (causes Lathril and your # of elves to grow exponentially each time Lathril hits an opp)

Fallen Ideal (similar to denizen. sac your tokens right before lathril hits to deal a ton more damage and make twice as many tokens as you had before)

Alpha Status

Pennon Blade

Coat of Arms

Fireshrieker

Cryptolith Rite

Song of Freyalise

Elvish Guidance

Harvest Season

Druids' Repository

Hunter's Insight

Ohran Frostfang

Hunter's Prowess

Return of the Wildspeaker

Patron of the Orochi

You may also want to consider Mobilize.

I noticed you took Wirewood Channeler out because of the cmc, but it adds to the redundancy of Priest of Titania and Elvish Archdruid to go infinite with Staff of Domination.

Thanks for upboating my deck. This may also do well with its own Jarad, Golgari Lich Lord in the 99. I know first hand having played elves since elfball was first a thing back in the tempest days that having an alt win con besides what is expected can make the difference. Jarad is a Fling on a Golgari Elven body. That wins games, a lot.

Also noticed you have 0 answers for a Wrath of God or similar effect. Westvale Abbey  ^Flip is a good option there just as at least a stand in to buy you time to rebuild a board state. It's a land first and a creature if it needs to be, so it's low to the ground. Fresh Meat can also fill this void but since it takes up an important spell slot it is less advised.

I like your list, i'm builing a Lathril deck too. Here are some of my suggestions:

A mana-cheap protection option could be delivered by Heroic Intervention . Malakir Rebirth  ^Flip and Bala Ged Recovery  ^Flip could be helpful too as they are pretty versatile cards.

If you want some recursion Phyrexian Reclamation could help you to rebuild booardstate after a boardwipe or t-removal.

What about Skemfar Avenger ? He's pretty cheap (in both ways) and would grant you pretty good card-advantage. An absolutely "must have" with that many 1/1's should be Skullclamp which could draw like your entire library. Realmwalker could grant you the top card of your library as a hand card as you can cast elf-spells from top of it.

Maybe you should think about Skyshroud Poacher too, which can tutor all of your elves repeatably for just 3 mana. Only Elvish Piper would be a mana-cheper option.

Gnarlroot Trapper is a perfect Manadork which can grant a creature deathtouch for protection as well. If your gameplan is winning by combat-dmg Beastmaster Ascension would be an absolutely blast.

I personally am not a bit fan of Nadier, Agent of the Duskenel and Eyeblight Cullers as their cmc is too high for what they cosst. Belbe, Corrupted Observer and especcialy Glissa, the Traitor don't push your gameplan any further, too.

Hope you don't mind my wall of text :D

Look for Alpha Authority it will make Lathril, Blade of the Elves imposisble to block, allowing her to spawn tokens each turn and also protect her with Hexproof

Second Sunrise is my preferred Board wipe answer when I'm running aggro

[SaintHipster] that's a white card...this is a BG deck...

If you want more of a buff voltron Lathril maybe switch out Incubation Druid and Heedless One for Immaculate Magistrate and Timberwatch Elf Those guys also can go off twice per turn with Copperhorn Scout

Crown of Skemfar Eldrazi Conscription and Bear Umbra are always good too if you're looking to take out beaters and focus on Lathril's abilities

Such a good List! I agree that balancing Lathril is hard (having so many choices makes it harder imo) but I like a lot of your choices and admittedly am a bit jelly of your Concordant Crossroads here... Though your mana base does make me feel kinda nervous xD

Just some input based on my own Lathril Deck:

If you want a one-sided Patriarch's Bidding you might want to try out Haunting Voyage - 7 Mana may seem like a lot but we are both, green and elves soo...

As in most token strats Skullclamp can do wonders for your card-draw! Sometimes, digging further into your deck is more important than some 1/1 Tokens.

I see that Heroic Intervention has been mentioned before. If you want a more budget option Golgari Charm can offer a similar effect.

On a recent Episode of "I hate your Deck" featuring a Lathril Deck, they played Vines of Vastwood which I am going include in my own deck as it doubles as protection or combat trick to get 6 tokens out of an unblocked Lathril.

Personally, I'd probably trade in some of the less impactful elves for staple removals such as Beast Within or Assassin's Trophy but that probably depends on your meta.

Misconception Thanks for the suggestion. Yeah the mana base is a little low. I mulligan a lot to get an opening hand with some dorks to help with that. As you mentioned "green with elves".

I'm keeping this lower powered. I started making it more "competitive" but I liked my marwyn elf deck too much and didn't want 2 high powered elf tribal decks

Umbra mantle…

You can check out my lathril build on my profile for ideas. Mine is more the competitive realm but you can get an idea

https://tappedout.net/mtg-decks/30-08-21-lathril-elf-ball/

SweetDreamsies I appreciate the suggestion. I actually used to run that and staff of domination but purposely removed them to get rid of infinite combos.

Feels like this deck will run out of gas straight away if someone boardwipes. I would certainly include more draw and removal.

Im also doing the same deck idea as you. I also dislike infinites, but i also dont tutor for wincons.

You run some protection agianst spotremoval, yet i dont see anything agianst boardwipes. My way of thinking:Spotremoval sets this deck back 1 turn. Boardwipes set it back to the stone ages.

My 2 cents