This deck is actually not one I own, just one I designed. My friend, who actually reintroduced me to Magic, had a way less consistent version of this deck, made seemingly of random cards in his small collection. After playing against it for a while and also getting a deck or two of my own made, I decided to help him upgrade his Merfolk deck. Here are the win conditions:
Aggro
When we first started playing together, this deck was in rough shape. It's main goal was to mill you using Drowner of Secrets. He focused so hard on this that he would not even attack when able. I actually had to teach him that he could attack. After playing him a few times since reminding him about combat I decided that this would be the most reliable and fast way to win in his deck. To build on this I added a bunch of AoE buff creatures like Merrow Reejerey, and more importantly Master of the Pearl Trident which combos with Aquitect's Will. His primary win con is now to set up an early defensive board and transition it into a massive unblockable swing.
Mill
As mentioned before, this deck's original focus was to mill. I wanted to keep this option so that his deck still felt like his desired flavor and personal touch. Also it isn't a bad 'Plan-B'. Now he can make decent sized (often unblockable) swings while keeping a board up thanks to Merrow Commerce. Then just before the turn passes back to him he mills you, getting double the value (or more with Judge of Currents) out of his creatures. This is typically just annoying to deal with and not the way he usually closes out the game.
Infinte Combo
This part was and still is pretty weird to me. In the original deck was a single copy of Wanderwine Prophets. At the time his deck did not have a reliable way to make him unblockable but it did have the ability to set up the turn loop using Summon the School, provided he had a large enough board at the start of the sequence. I left him in because he should have a much easier time actually establishing his turn loop and again to maintain the identity of the original deck. This card is by far his least common way of winning.
In Conclusion
The original deck was pretty jank. This version of the deck is really fun (annoying) to play against. It is definitely far more simple than it was before but it is also much more reliable and deadly. Like I said at the begining, this is not a deck I actually own so I'm not at liberty to take suggestions. Do still feel free to give your opinions though!
