4x
Rakdos Cackler. This one will probably get some weird stares. This card has never seen competitive play in modern, or any format except standard and penny dreadful. However, i am running a full playset. Cackler has synergy with Mogis's Marauder by the fact that he has a hybrid mana symbol, so he ran be reanimated late game in the final attack and given haste/intimidate to help close out a round. To explain why I run cackler over other 1 drops, I kind of have to explain the current modern metagame. The one drops in red you see the most are listed with why I don't run them:
Ragavan, Nimble Pilferer: This card is super expensive. But for good reason. It is literally considered one of the best one drops in modern right now. However, there are advantages that cackler has over it, such as 2 toughness, and the ability to cast it with a black mana. Sadly these are the only reasons. Ragavan even has the added bonus of being able to dash in for 1R with haste, having an ability that gives you a treasure token, exiles the top card of your opponents library for you to cast, AND can have 2 power without giving away his ability to block. Yep, If it weren't for the price tag on Ragavan, he is quite literally just better in most situations.
Dragon's Rage Channeler: Dragon's Rage Channeler is a pretty good 1 drop in its own right. It has surveil 1 which allows you to look at the top card of your library and put it in your graveyard. Then with delirium, it can become a 3/3 flyer that attacks each turn. This card is cool because it can allow you to set up your graveyard for reanimation, and becomes a 3/3 flyer after proper setup. Unfortunately I find this card to fall short in the deck. First of all, its a 1/1 for 1. Granted, it can be a 3/3 with setup. However many effects of this deck rely o either A: reanimating creatures, or B: exiling cards from your graveyard. Both of these reasons explain why dragon's rage channeler goes against the basic fundamentals of the deck and what it desires to achieve. Playtesting with this card showed it to be hard to get these effects off consistently.
Goblin Guide: This is a HEAVY contender for cacklers slots. Goblin guide is a 2/2 haste creature that forces the player it attacks to reveal the top card of their library and if its a land, they add it to their hand. Goblin Guide has haste, making him faster then cackler, and is still a 2/2. The only downsides are that Goblin Guide has to be paid with a red and that it can give your opponents card advantage. However for most people, these downsides will probably be worth it.
Monastery Swiftspear: For me, Switfspear doesnt fit at all. Its a Haste 1/2 with prowess so its as tanky as cackler and can attack turn one. The only downside in this case is prowess. If this were burn, this would be a instantly better upgrade (although you might think it's better in this deck also). But the way I see it, you don't have the mana in this deck, nor the burn spell slots, to make this card work.
In conclusion for cackler, you may find any of these options to better suit your build and that's fine. I like cackler for sentimnental reasons but I understand that he might seem a bit worse than other options. If you really want the minor competitive adjustment, just slot him for what you like.
4x Dauthi Voidwalker: Voidwalker is a great include in the deck for its stat line and shadow. A 3/2 or BB with shadow is pretty darn cool. Not to mention it becomes a counter to graveyard based decks for its effect which exiles all cards your opponent's lose. It even exiles them with a void counter so you can even sack him to play any of those cards for free.
