I have made A LOT of subclasses on this site and I do my best to make them balanced and fun. 
It’s taken me a very long time to figure out how best to bring this fighting style to life but without further ado I present to you my fighter subclass, “The Survey Corps”. Have you ever wanted to use magic grapple hooks to hurl yourself across the room at an enemy? Have you always wanted to turn yourself into a thunderous smite? Then please click the link below and check out my subclass, I appreciate your time.

Tell me what you think below and if you like it please give it an add, an upvote, and share it with your friends.

*I’d like to add that I am acutely aware that someone might report this class and get it taken down. Or that it may have bugs that I can fix. Let me be clear, I will do whatever it takes to keep this subclass live for you, I will rewrite anything and fix any bug. This has been a power fantasy of mine and I’m sure for you for a long time. Keep an open channel with me and I will make sure that this subclass is amazing*

https://www.dndbeyond.com/subclasses/717790-the-survey-corps

the odmg feature says (might be typo) that your  vulnerable to opportunity attacks which have disadvantage against you BUT are automatically critical if they hit(while jumping)  i see no reason to attach such strong weakness at this level as i could easily see this killing a player at the level you get it 

Quote from stuffattackknightofrandom >>

the odmg feature says (might be typo) that your  vulnerable to opportunity attacks which have disadvantage against you BUT are automatically critical if they hit(while jumping)  i see no reason to attach such strong weakness at this level as i could easily see this killing a player at the level you get it 

 I completely see where you’re coming from and I agree that it is harsh. I included this feature so that there was a sort of glass cannon feel to the class. Like your momentum helps you do more damage but it works against you too. I also hope that it encourages players to use more crative paths with their jumps to avoid taking an opportunity attack.

If you are using this subclass and the feature becomes a problem in your games I’d encourage you to ignore it and use your own rule. Additionally if this becomes a widespread problem I will be happy to patch it with a different system.

okay just maybe only vunerable or crit not both

Okay, I hope my feedback is helpful. I'm sorry if it isn't.

1. For We Are the Hunters, the feature itself is balanced, but I would reword it to, "When you choose this archetype at 3rd level, once per turn, when you deal damage with a melee weapon attack against a creature that is at least one size larger than, you may add your proficiency bonus to one of the attack's damage rolls."
2. Endurance Training is pretty good, but not overpowered. I would just reword it slightly to, "Beginning at 3rd level, the extreme training you undergo to be part of the Survey Corps gives you increased endurance. You have advantage on Constitution saving throws.
3. For ODMG, I would remove the vulnerability to opportunity attacks, otherwise and monster with a decent to hit bonus will be dealing 4x their regular damage whenever you move. I would also change the way the features are worded to, "As a bonus action, you can activate your ODMG. For ten minutes or until you drop to 0 hit points, you gain the following benefits:
   • When you take the attack action, you can jump in place of one of your attacks. When you jump, you can travel a distance equal to half of your walking speed. Opportunity attacks that target you while you are jumping have disadvantage, but any opportunity attack that hits you is a critical hit.
   • If you end your turn in the air, you can slow your descent using your grappling hooks, provided their is a Large or larger solid object within 30 feet of you. While delay your fall in this way, you descent at a rate of 10 feet per round, and while you are still airborne, you can use a bonus action to suspend your fall.
   • When you jump, you build momentum behind your attacks. When you jump, you add 1d10 damage to your next melee weapon attack, provided that it occurs on the same turn as the jump. This damage increases to 2d10 when you reach 12th level in this class. Damage granted by this feature is considered magical for the purpose of overcoming resistances and immunities to nonmagical damage. 
     Once you use this feature,  you can't use it again until you finish a short or long rest.
4. For Veteran of the Corps, I would recommend allowing them to ignore difficult terrain, as well. Otherwise the ability is a bit underpowered for its level.
5. For Efficient Tanks, I don't have many suggestions. The feature is pretty nice, and it's very thematic as well, just like the subclass' other features.
6. Perfect Critical is pretty good, but you might want to add another small bonus.

Quote from Thauraeln_The_Bold >>

Okay, I hope my feedback is helpful. I'm sorry if it isn't.

1. For We Are the Hunters, the feature itself is balanced, but I would reword it to, "When you choose this archetype at 3rd level, once per turn, when you deal damage with a melee weapon attack against a creature that is at least one size larger than, you may add your proficiency bonus to one of the attack's damage rolls."
2. Endurance Training is pretty good, but not overpowered. I would just reword it slightly to, "Beginning at 3rd level, the extreme training you undergo to be part of the Survey Corps gives you increased endurance. You have advantage on Constitution saving throws.
3. For ODMG, I would remove the vulnerability to opportunity attacks, otherwise and monster with a decent to hit bonus will be dealing 4x their regular damage whenever you move. I would also change the way the features are worded to, "As a bonus action, you can activate your ODMG. For ten minutes or until you drop to 0 hit points, you gain the following benefits:
   • When you take the attack action, you can jump in place of one of your attacks. When you jump, you can travel a distance equal to half of your walking speed. Opportunity attacks that target you while you are jumping have disadvantage, but any opportunity attack that hits you is a critical hit.
   • If you end your turn in the air, you can slow your descent using your grappling hooks, provided their is a Large or larger solid object within 30 feet of you. While delay your fall in this way, you descent at a rate of 10 feet per round, and while you are still airborne, you can use a bonus action to suspend your fall.
   • When you jump, you build momentum behind your attacks. When you jump, you add 1d10 damage to your next melee weapon attack, provided that it occurs on the same turn as the jump. This damage increases to 2d10 when you reach 12th level in this class. Damage granted by this feature is considered magical for the purpose of overcoming resistances and immunities to nonmagical damage. 
     Once you use this feature,  you can't use it again until you finish a short or long rest.
4. For Veteran of the Corps, I would recommend allowing them to ignore difficult terrain, as well. Otherwise the ability is a bit underpowered for its level.
5. For Efficient Tanks, I don't have many suggestions. The feature is pretty nice, and it's very thematic as well, just like the subclass' other features.
6. Perfect Critical is pretty good, but you might want to add another small bonus.

 WOW. Thank you. Seriously. These are all really good suggestions especially for the wording. I’m usually pretty good at mechanics and balacing but the wording is much more difficult. If it’s ok with you I will go through and make a hotfix tonight with the new wording. It’s much better than mine. 

As for the vulnerability I see that this one is bugging more people than I thought it would so I will remove it. This way you can still be attacked, it won’t be critical, but it won’t be at disadvantage anymore.

I've made a new version of this subclass using a fair few suggestions and a major upgrade in the grammar. The class' mechanics are now less wordy and more balanced toward dnd 5e as a whole. The link above has been updated and an additional link can be used HERE. A big thank you to Thatraeln_The_Bold for their help and suggestions.