The Mato Mato no mi aka the Mark Mark fruit is the fruit that no one's favorite character, Vander Decken IX, is the user of. As you probably know this bad boy allows the user to be able to simply touch something and then it will be marked, when something is marked then you can throw any object towards the target and then the object will fly all the way to the target until contact or being blocked by an outside force. Now creativity is the best weapon in the One Piece universe and some fruits sound meh but if you use your noggin then they can be pretty damn effective. One thing you can do with this fruit is that if you can get some scientist or someone like Caesar to create a very small or multiple very small capsules of poison gas or a virus that would be difficult to detect, now when you throw these capsules they will hit the target and then bam the target will be poisoned without noticing. Now another thing is that you could do what they did with the Noah and make a large object go towards the target, now for this one you could do something like throw a giant rock or whatever is in your area weather it be a house or a boulder, now if your enemy is strong and can destroy that, then you could either distract them with the large object then throw something small like a knife or one of those poison capsules at them so they wont notice and be hit. Now another one is by throwing a person, now imagine if Luffy or Zoro or Sanji were your ally, that would be great for you since you could toss one or maybe all three of them at your target and they will be able to destroy any obstacles and do heavy damage upon impact.