Dredge is best described as a midrange deck with combo elements. Against interactive decks Dredge generates card advantage with recursive threats, while interacting with the board thanks to Conflagrate. It is described as having combo elements because of the occasional fast draw it can generate when it finds its Prized Amalgams quickly. How powerful Dredge is at any given point is often related to how much graveyard hate people are playing. If you can dodge seeing cards like Rest in Peace and Leyline of the Void, this deck is very good. You can read more about Dredge on Star City Games here and here.
This is probably the deck I am most Internet famous for. I was paid a large sum of money to play this deck at an SCG open in an Owl Costume. It is a total hoot and if you enjoy sending your opponent’s cards back to their hand I would highly recommend this one.
Jeskai Ascendancy Combo, or JAC for short, is something that I can best describe as “interesting storm”. While it is a linear combo deck, the way we end up winning the game each time we play it is going to vary. Generally speaking we draw through our deck with cantrips and Jeskai Ascendancy loot triggers, while powering up our mana creatures to attack with. You can read my full primer about this deck on Gathering Magic here. You can also talk about this deck in the JAC discord server here.
This is a degenerate combo deck that is capable of winning the game as early as the first turn. It does so by putting Griselbrand into play and then drawing piles of cards. Thanks to Nourishing Shoal along with Worldspine Wurm, we can often draw our entire deck. This lets us use our fast mana to put Borborygmos Enraged into play as well to kill our opponent by discarding lands. You can find some sideboarding notes for those archetype here.