Note: This deck definitely is lower tier but FUN to play and can still win out of nowhere with the combo. So yes, it is in not very competitive, don't say I didn't tell you. Anyway, it can wipe the floor with anything big and rampy at least after side-boarding, it struggles a bit against aggro and weenies, so a sideboard upgrade with more board-wipe options could be a thing.

Key cards

How to play

Empty your hand, get in trouble (going down to 1 happens more than you think) then find your combo-bail-out with Mausoleum of Secrets and Castle Locthwain. Also if your opponent thought they were up against knight-tribal prank them with the Rankle, Master of Pranks.

About the latter: Drawing from the castle is good in grindier matchups and keeps you ahead in top-deck-mode but it needs 4 mana, sometimes playing around this feels awkward. Don't be afraid to castle draw after a bad draw step late-game if you could get the combo off. Rankle also helps filtering excess lands but don't be afraid to pay life, there's plenty of life gain in this deck Cavalier of Night will just sit there and keep the board in check.

Usually it's better to go for value and mana-efficiency, don't skip turn two if smitten is your only play, you can let him die, gain two life and get him back later with Order of Midnight.

Actually Clover + Order + two Swordmasters in the Graveyard isn't the worst position to be in if you still have some knights on board or you're able to squeeze in another one-drop. This is also where Rankle comes in as he can help with getting Swordmasters to the yard. 

We mostly run spot-removal so you'd usually use your creatures to block, only turn them sideways if you need to trade for life or want to cycle some adventures from you graveyard.

Sideboard and Options

 Against green just remove all the tribal/combo-pieces and go full removal/control mode with with Noxious Grasp but keep Order of Midnight to get Rankle back. Against everything else you got the standard sideboard package with Legion's End and Duress, tweak that to your taste. You might want to consider adding more Witch's Vengeance or swapping it with Massacre Girl if you take out Swordmaster your creatures become sac-fodder anyway. I had Icon in the deck before and it is very slow, Heraldic Banner could tick up the Rankle clock a lot and ramps you into the Cavalier but it also feels slow. Despite the curve, there's a lot to do with 3 mana in this deck, no need to cramp that spot too much. Just think of Profane Insight, as you can leave up 3 muana instant-speed or cranking up the Knight of the Ebon Legion. In any case Cavalier usually stands tall against a Questing Beast, just never have anyone Embercleave you.

Note that casting adventures off Lucky Clover fizzles against control, but the copies will resolve, so no need to take out the combo. Also you might want to consider deliberately fizzling Swift End by choosing the same target multiple times, you will only loose 2 life and can get the Murderous Rider back from the yard with Alter Fate.

Big thanks to CovertGoBlue and SBMtG for providing some guidance and ideas in their channels for this deck. They have some variants of the deck for CGB for BO1 Arena and SBMtG a Golgari version running Innkeeper. But OUAT got banned and Innkeeper's not a knight so I think that version of the deck died with it.

MK II Changes:

- Get rid of icon and heraldic banner, they are slow and clunky and you don't need the ramp, also the 3 mana slot is occupied by abilities and adventure spells aalready.

- Remove Midnight Reaper: Just to clunky and too much train in the early game. Also 3 mana slot needs to be kept clear for Knight of the Ebon Legion, Profane Insight, Swift End and various 2+1 plays.

- Update side- and maybe board for better board wipe options.