chaoslord00

I think the combo is too weak to any kind of disruption, whether it be hand, burn, removal, counters, etc... It's good for a fun deck but it fails to be competitive.

You should use Jace and have Kiora in the deck. Jace ultimate for Kiora and your opponents win conditions and then get her ult too..

Spreading Seas doesn't have no effect. As raging said, replacing itself is important. Next, it can remove 1 or 2 colors from their mana pool as well as harm Domain decks. Finally, it synergy with your lords, Lord or Atlantis and Master of the Pearl Trident, makes your creatures unblockable because they have an Island. With the resurgence of naya zoo in modern, Spreading Seas has become more powerful if you ask me.

Similarly, Silvergill Adept draws, replacing itself. It is also a 2/1 merfolk which has synergy with your lords, getting boosted and Islandwalk. Phantasmal Image x4 should be in here too and it can be used to draw a card if you need by copying Silvergill.

As others have said, Silvergill Adept in, and it would make fixing draws less important. Halimar depths comes into play tapped and lets your opponents stabilize. Fixing draws becomes less necessary with a 4-pack of Silvergill Adept and Spreading Seas which is why I commented on the lack of a full set of Spreading Seas above.

I noticed that after what Chronoexe said but the edit timer on the comment ran out. The deck is Tagged Tribal which is what made me believe it was Tribal. I didn't read beyond the 3rd tag since it Said [Tribal] [Merfolk] and the deck had cards not available in standard.

Technically sideboards aren't allowed in the Tribal format.
Silvergill Adept lets you draw a card when you play it so you can get some card advantage.
Running all the Spreading Seas in the main to get card advantage if the enter the battlefield. Islandwalk is relevant.
Coralhelm Commander is too slow to be running more than 2.

I believe Mana Leak is less effective for you since your lords and Spreading Seas are CMC 2 and you're an aggressor. Mana Drain might be a better choice if you keep all the Coralhelms because you have plenty of colorless in your costs. Daze can set your opponents back as well as play around future dazes and it doesn't hold you back from being the aggressor. Remand can set your opponent back a turn and gives card advantage.

Julian, war is not some game like chess where ever piece is a soldier. Pawns at most might be soldiers but it's more likely that only half the pawns would be soldiers, making one-fourth(at most), the units in war Soldiers.

War has happened to other creatures and races. It doesn't take shape just because the fighters are humans, and it can be caused by any number of reasons. The crusades were wars with no soldiers. Cold wars are fought with possibilities, not lives. Monarchy wars were fought with assassins that killed the king, leading to the end of the war. War has an unlimited number of shapes and colors, and are described by the victor.

Anyways; Do you have Elspeth, Sun Champion instead of Elspeth Knight-Errant. She gives more units for +, large explosions for -3, and pump for ultimate. Also, what format are you looking for playability in?

Your lack of war is disturbing. I expected more than just soldiers and the lack of Elspeth in the presence of speaking of soldiers is blasphemy against war itself! I especially expected the red-white hybrid card that has retrace, Waves of Aggression.

Soldiers are a joke when speaking about War. More than soldiers, there are assassins, mercenaries, war-beasts(giants, griffins, behemoths, griffons), and more. Humans are the most distasteful creatures because they believe themselves on top of the food chain, willing to trick and enslave others, sending them off to battle on their own behalves. A horseman of hell wouldn't cause soldiers to fight, he would cause every living race to engage in war, and the dead to feed on the living. With that in mind, Xathrid Necromancer would no doubt help in the making of such a deck. :)

Whether you keep it like it is or change it to any number of ways one might build a true deck of the Horseman of War; Good luck. I hope you settle for something you like and can hold your head up high saying "This is a deck I believe to be a representation of the Horseman of war."

Not to say anything bad but the truth is that Green-Red works better only because of Burning-Tree Emissary. It is also why Green-Red Nylea Devotion is a thing. Kiora's Follower is significantly weaker in this deck merely because you can't cast it off Emissary like you could Voyaging Satyr. This makes your early game much weaker. I think you need to shape up it's early ramp a bit different.

Good luck on getting this deck to make up for that disadvantage.

You should replace Gauntlet of Power with Gauntlet of Might.

Lotusbloom is right. Karametra would've been better for this if the land entered your hand but sadly it enters the battlefield.

Fade into Antiquity is strictly better than Glare of Heresy.
Merciless Eviction fits more than Fated Retribution?
I like Ready // Willing but I don't know whether it fits here. I can seriously see it blowing people out.

Many people I know alternate between Snow Lands and basic lands because people use the Lens + Snow combo so it's 50-50 whether other people may benefit in my group.

I think it needs some ways to draw. Wheel of Fortune effects are quite good from red once you empty your hand. :)

Running 1 of win conditions is asking for your combos to be shut down.
Acquiring a Boros Charm in conjuction with Aetherling and tokens is very unlikely when you only run a total of 3 of them.
Expecting Chandra to get there on her own without some defense is quite unlikely without some tougher instant speed removal.

I don't see any real answers to green and red aggro decks in your choices apart from Verdicts after taking significant damage.

American is what most people who don't know about the -volver's call the RedWhiteBlue decks. There's a lot of different ways to interpret it all.
Each pair(2) of colors has a guild.
5 of the 10 trinity(3) are Jund, Grixis, Naya, Esper, Bant. The other 5 of the trinity's are called by many many names. The apocolypse set had 5 volver cards; Ana(green blue black), Ceta(red green blue), Dega(red white black), Necra(green white black), and Raka(red white blue). These 5 are also called by the name of their respective dragons by some and ugly names like Junk, American, RUG, BUG, etc.
The 5 4-colors are usually distinguished by the Nephilim names.
5-color tends to be called 'five color' or things like Maelstrom or Conflux.

You're running at least 1 too many 3-mana hard counters.
Boros Charm doesn't fit as much as you might want it to.
Aetherling needs a friend?
Ral Zarek is an burn-style izzet planeswalker, and this is supposed to be a control deck?
Gothy pointed out that Jace, Architect of Thought is a control-oriented planeswalker.
Mizzium Mortars makes me confused alongside a stack of Supreme Verdicts. What's your reasoning?

For a deck that pumps out X/1 tokens, the lack of Skullclamp is a bit depressing. I can definitely see you falling behind in card advantage quite fast.
Have you considered Martyr's Cause? It gets around nasty things like Hexproof, Shroud, Protection from Players, Protection from Everything, etc, and you have plenty of tokens to offer up!

Jin-Gitaxias was never an option. Kaalia can't drop him and you don't draw until right before you discard. Also, you opponent has a whole turn to have an answer to him before he has to discard since none of your reanimate spells are instant speed.

Demon of Death's Gate lost his spot when you dropped the low-costing black drops you had.

For your lands, I recommend at least: 4 Dragonskull Summit, 4 Isolated Chapel, 11 Swamp, 2 Mountain, 1 Plains. If you insist on only basics, I believe 11 Swamp, 6 Mountain, 5 Plains could work.

You have no hand disruption or mass removal. I recommend at least 3 mass removal and 4 of either normal removal or hand disruption. The mass removal could be Divine Reckoning or Damnation. The removal or hand disruption might look like a choice over Mortify vs Thoughtseize.

Rather than Boomerang, people run Disperse, Echoing Truth, or Chain of Vapor. I could see some sideboards including Wipe Away but very few would Cunning Wish for it but it would cost 6 mana so ideally you'd have a better chance of going off.

My Squirrel Nest deck is unlisted: http://www.mtgvault.com/chaoslord00/decks/vn-squirrel-nest/
I'm not proud of it but it's quite mean if you ask me. The sideboard has answers to Wipe Away users. ;)

You should have already won before the time you cast your 4+ CMC cards.

I think Firemane Avenger lost it's spot in this deck. You dropped much of your lower creatures so the chance for battalion dropped from very possible to unlikely status.

I think you need more survival tactics early on. Ethersworn Canonist is good at slowing the game down and your build is about casting basically 1 spell a turn so it wouldn't be too restricting.
Linvala, Keeper of Silence and Stony Silence can slow down combos until they remove your stopper. Dampening Matrix works well in both of their steads but you can fetch Linvala to your graveyard from your deck with Entomb and then Exhume it the next turn.