Perhaps someone (maybe @fazool) with a fake stamp can take some close-up scans of it so we can see how a fraudulent stamp compares to a real one
Things like Gravecrawler and Kitesail Freebooter are your friends here
We do have sacrifices and creatures that trade in combat, so it definitely can happen, but theres a chance Noctis, Prince of Lucis isnt very effective, and at three colors it takes a lot to put Noctis into a deck in the first place
Some options that are very strong to build around if youre looking to play saboteurs are Felix Five-Boots and Mirror Room // Fractured Realm
Upheaval This board sweeper resets the entire game back to square one for only six mana, which would be problem enough and when you factor in all that mana you floated and are about to recast your mana rocks, its chances only get worse
With that said, four mana is a large investment