This mega knight miner deck is very strong in the current meta. The mega knight is the control card in this deck and should only be used defensively unless you make an unbelievable early counter and your opponent does not have their counter in hand. The miner chip aspect of this deck is very powerful as well and pairing that with poison is hard to stop. Another fantastic thing about this deck is that there is a skeleton barrel and royal ghost in the deck. The barrel tanks for the miner, and when it pops, the miner tanks for the skeletons. The ghost must always be responded to and it cant be taken out with squishy troops because of the splash. The bait is strong with this deck because opponents will try and zap the skeletons, bats or inferno dragon. This deck is especially strong in double elixir. After countering nicely with the mega knight, counter attack with the barrel and use the miner to take out other cards or just go in for damage.
The mega knight is the controller and should be used defensively for a nice counter attack. You can use it on offense if you made an extremely valuable trade and the opponent's counter is out of hand.
The miner should be used to attack elixir collectors and bait your opponent to attack you. You want them attacking so you can use the mega knight to crush them and counter back.
The skeleton barrel is awesome because you can use it to tank for the miner, and then have the miner tank for the skeletons. This can be annoying to stop because there are a few different cards in your deck which will be zapped.
In the early game, you should use naked miners to bait out an offensive attack from your opponent. If they give you a lot of elixir to stop, crush it with the mega knight and counter push. Don't over commit early on and just slowly chip with the miner. Even playing a ghost by itself is viable because there has to be a response.
In the late stage, the miner and poison combo is great at giving you a lot of value. Get value and super counter with the mega knight, barrel, and the ghost. The ghost helps to clear the path, and by then, you will have time and cycle back to another miner poison combo.