Operatives

[Lunar Origins]

Mark

Spell | Quickplay

Cannot be discarded by card effects.  If this card is in your Graveyard during your opponent's Standby Phase:  Set this card in your Spell/Trap zone.  Target 1 Monster on the field;  Place 1 Mark Counter to that card.  While this card is in your Graveyard:  Double the ATK of all monsters your opponent controls with Mark Counters, and if a Monster your opponent controls with a Mark Counter battles an "Operative" Monster:  Switch the ATK and DEF of those Monsters, then remove all Mark Counters from Monsters in that battle.

 

Harrier

Spell | Continuous

When this card is activated:  Add 1 "Mark" from your Deck to your hand.  Each time a Mark Counter is removed from the field:  Add 1 "Operative" Monster from your Deck to your hand, then you can send 1 "Mark" from your Deck to your Graveyard.

 

Assassinate

Trap

Target 1 Monster on the field with a Mark Counter:  Banish that Monster face-down.
 

Informant

Trap

Set 1 "Mark" from your Deck.  While this card is in your Graveyard, if you activate "Mark":  You can Special Summon 1 "Operative" Monster from your hand.

 

Operative Caeling

DARK | Level 6

[ Warrior / Effect ]

If a monster your opponent controls has a Mark Counter:  You can Special Summon this card (from your hand) in face-up Defense position.  Once per turn:  Target 1 Monster your opponent controls with the highest ATK (or all monsters your opponent controls with the highest ATK);  Destroy that target(s), then return this card to your hand.  You can only use this effect of "Operative Caeling" once per turn.

[ ATK: 0 / DEF: 2500 ]

 

Operative Umbral

DARK | Level 4

[ Warrior / Effect ]

FLIP:  Send 1 "Mark" from your Deck to your Graveyard, then, if this card is flipped face-up because it was attacked:  Target 1 Monster on the field; Add 1 Mark Counter to that target, then switch this card to Attack position and redo the battle.

[ ATK: 500 / DEF: 1200 ]

 

Operative Sieglinde

DARK | Level 4

[ Warrior / Effect ]

When this card is Normal Summoned:  You can Set 1 "Assassinate" from your Deck in your Spell/Trap Zone, then place 1 Mark Counter on 1 Monster your opponent controls.  If this card is destroyed and sent to the Graveyard:  Shuffle it into the Deck, then you can send 1 "Mark" from your Deck to the Graveyard.

[ ATK: 1800 / DEF: 1400 ]

 

Operative Pascal

DARK | Level 3

[ Warrior / Effect ]

FLIP:  You can activate 1 "Mark" from your Deck or Graveyard.

Once per turn, during either player's turn:  You can target 1 Monster on the field with a Mark Counter; Return that card to the hand, then Set this card.

[ ATK: 1900 / DEF: 1200 ]

[Dramatic Crossroad]

Most of these are wildly unbalanced. They have great synergy ,but planned to work all too well without any drawbacks, making them OP.

 

Suggestions:

- Add condition to "Assasinate", for instance controlling a Operative monster (the one who will conduct the assasination).

- Limit the activation of "Harrier" to once or up to twice per turn. Unlimited +2's are not too realistic. 

- Add condition to "Informant" as well, like when your opponent Special Summons a monster (good time to select a target for assasination isn't it?). Limit its graveyard effect to activate once, since you will be playing "Mark" like crazy. 

- Caeling's effect is troublesome as well. You can keep spamming it over and over killing your opponent's strongest monster, while keeping a weak one with a mark counter on the field. If you add a condition to the bounce effect it would be more plausable, like "destroy the monster with the highest ATK on your opponent's side of the field (your choice if tied), and if that monster had Mark Counter(s) - return this card to your hand". 

- Pascal - a level 3 monster with 1900 ATK and myriad of effects with no drawback = OP.

 

- Mark is so broken, in all kinds of way... it needs a paragraph on its own. 

Setting itself without a cost without limitations, you can indefenetely spaw 3 of these during each of your opponent's turns... Even the thing you added to balance things off is purely conditional and easily manipulated with its own effect a.k.a. If you played Mark during your turn and set it during your opponent's SP. Apply the ATK x 2 for each Mark Counter and attach that effect to the counter and not to "this card being in the graveyard". Also the last sentence of the effect is too vague when it comes to playing it out, you would need to remove the Mark Counter at the start of the battle step, not at the end of it, otherwise your monsters are at a huge disatvantage, plus again - this effect is only triggered when Mark is in the grave, something you cannot always rely on.

It's unclear if and what happens, since you mentioned both your opponent's monster and the Operate monster, do they switch their own ATK with DEF, or the values between each other?

Example:

 

Your opponent's Luster Dragon [1900/1600] with a Mark Counter attacks your O. Umbral [500/1200]: 

a). their own ATK is switched with their own DEF: 

(Luster)1600/1900+mark counter => 3200/1900 vs 1200/500(Umbral), then they battle, your Umbral is destroyed and then mark counters gets removed, and Luster Dragon's stats become 1600/1900, since it's never mentioned the switch lasts only for the duration of the battle.

b). they switch ATK and DEF with each other: 

(Luster)500/1200+mark counter => 1000/1200 vs 1900/1600(Umbral), they battle, then the mark is removed, but it doesn't matter since your opponents monster was destroyed by the battle. This way the highest ATK/DEF stats can bounce off your and your opponents monsters indefinitely as long as Mark is in your grave.