Rouge, Warrior of Acheron

[Psyche]

Master of War
When you choose this archetype at 3rd level, you gain proficiency with Smith's Tools, the dragon chess set, medium armor, shields, and martial weapons.

Master of Tactics
Starting at 3rd level, you can use the Help action as a bonus action. Additionally, when you use the Help action to aid an ally in attacking a creature, the target of that attack can be within 30 feet of you, rather than 5 feet of you, if the target can see or hear you.

Master of Offense
Starting at 9th level, you can attack twice, instead of once, whenever you take the Attack action on your turn. Moreover, you can use the help action in place of one of those attacks.

Master of Defense
Beginning at 13th level, as a reaction, you may add your proficiency bonus to your AC, possible causing the attack to miss. If the attack hits you, you can still use uncanny dodge on the damage of that attack. You may use this ability a number of times equal to your proficiency bonus, and you regain all uses on a short or long rest.

Soul of the Warrior
Starting at 17th level, you may apply half your sneak attack damage to the second attack you make with your master of offense feature, provided you meet the prerequisites of sneak attack for the second attack

[Amechra]

Looking over this... Master of Offense is pretty much worse in every way than just sneak attacking normally. Not only is it going to usually deal less damage overall (yes, even if you're using it to Extra Attack with a greatsword or some other similar weapon), but it prevents you from Sneak Attacking until the end of your next turn for some weird reason.

Also, Master of Defense is currently useless — you use Uncanny Dodge after you get hit.

[animorte]

Looking over this... Master of Offense is pretty much worse in every way than just sneak attacking normally. Not only is it going to usually deal less damage overall (yes, even if you're using it to Extra Attack with a greatsword or some other similar weapon), but it prevents you from Sneak Attacking until the end of your next turn for some weird reason.

Also, Master of Defense is currently useless — you use Uncanny Dodge after you get hit.

What? How? It looks to me like that provides two opportunities to land Sneak Attack, similar to what two-weapon fighting or crossbow expert might offer.

I agree with your comment on mark of defense. Maybe just remove the uncanny dodge from that altogether and allow this ability to be used x number of times equal to proficiency bonus, regain on short rest.

Overall it’s a very straightforward, more front line focused support Rogue. I like it.

[Amechra]

What? How? It looks to me like that provides two opportunities to land Sneak Attack, similar to what two-weapon fighting or crossbow expert might offer

It looks like Psyche edited both Master of Offense and Master of Defense after my post (thereby making me look crazy...)

[animorte]

It looks like Psyche edited both Master of Offense and Master of Defense after my post (thereby making me look crazy...)

I didn’t check the time stamps myself, haha. Psyche is good at updating stuff based on solid feedback.