Shovel Knight: Treasure Trove

Some notes on how to approach this to make it easier:

-Have the Phase Locket and 2 Ichor's of Invincibility: The 20 seconds total of invincibility will help you not get hurt for the most part, but the phase locket can make big difference in having an attack miss you

-I personally fought the King Knight for this achievement, but I'm sure others are possible and could potentially be easier (Mole Knight isn't too hard for the most part at least in my opinion).

-You cannot get hit and then heal yourself to full health with an Ichor for the achievement to unlock. I did that once against King Knight and the achievement did not unlock.

-Practice makes perfect. Learn the bosses patterns and get used to the dodge you need to do. I fought King Knight 3 or 4 times to learn and be able to earn the achievement.

NOTE: The Black Knight on the Plains does not count. He is not a member of the Order. It must be one of the other 8 Knights (King, Specter, Mole, Treasure, Plague, Polar, Propeller, or Tinker).

First off, I suggest going into options and switching your relic activation to Button mode so that you only have to tap to use relics rather than having to use the left thumbstick/d-pad and button combo. It makes the entire game much easier IMO.

This can't be done on the first mission as it isn't an Order of No Quarter mission. Therefore, I suggest doing it on the very next mission, Pridemoor Keep, against the King Knight. Make sure you have the Phase Locket relic and two goblets with the troupple king's ichor that refills all your health and magic. I'd also suggest having a few magic reservoir upgrades before attempting it. When I did it, my maximum magic was 90 which isn't huge but is plenty combined with two chalices to refill my magic. Run through the mission until you reach the King Knight. As soon as the fight starts, activate the Phase Locket IMMEDIATELY as he jumps right at you at the start. Keep activating it any time he's anywhere near you or you're jumping toward him to attack. I'd suggest attempting to jump above him and do the downward-bash attack to keep bouncing off his head, as it's much harder to time straight-up shovel swings and have them connect, and you don't want to run out of magic using it constantly to attempt that.

A great time to get lots of damage in is when he uses the confetti trumpets. Jump over him and keep bouncing off his head, making sure to keep your phase ability active so it doesn't fade right as a piece of confetti is about to hit you. I would suggest activating it after about 1.5 seconds, before the previous use even finishes, during these portions as you can get nailed by confetti pretty quickly after it runs out without realizing it. Also, when you see him do his jumping slam attack, jump into the air and activate the Phase Locket. This keeps you sort of hovering in the air for a second, long enough for him to slam the ground. If you're on the ground when he slams, you get dazed and invariably take a hit.

In the interest of creating as much of a one-stop-shop as possible, I've included 22 of the miscellaneous achievements in Shovel Knight in the video below. I wanted to include Knuckle Down as well, but the stage for that was already complete in my game and I haven't played back through again to unlock it. You can see a playthrough of the King Knight boss fight using this strategy at the 21:42 mark.