I just have to say that I love this thread. I think we're on to a real winner for "Format of the year" here. It's an entirely new challenge making deck as awful as possible. That said, I submit this monstrosity;
4 x
Electric Eel2 x
Fugitive Wizard4 x
Kruphix, God of Horizons2 x
Security Detail3 x
Horror of Horrors4 x
Fireforger's Puzzleknot4 x
Psychotic Haze2 x
Cut the Earthly Bond4 x
Trip Wire2 x
Mana Matrix3 x
Adarkar Wastes4 x
Flooded Strand4 x
Skyshroud Forest4 x
Yavimaya Coast14 x
SwampI'm pretty sure it ticks all the boxes. 10 creatures (4 of the same legendary that can only attack if you can get 5 of the remaining 6 creatures down, all of which are 1/1's, and all of which are going to hurt you because all the mana is pain)
10 other sources of damage (premium burn in the form of puzzleknot (which can be cast, but the second mode can't be used to get an additional damage, making it 1 damage for 2 at sorcery speed), psychotic haze (at the even more premium 4 mana for 1 damage, including to yourself and all your creatures (hope you didn't have 2 of those blue dudes out, or kruphix can no longer ever attack) and the security detail creates 1/1s, but only if you hurt yourself for 3 first. And then you can't use it again until the creature dies.
Excellent removal in the form of trip wire and cut (I wasn't sure if the puzzleknot/haze counted, as they can both technically do damage to creatures, so I played it safe and kept 6 distinct removal options).
The rest of the deck is jank that does nothing but meet requirements for 6 drops and colourless stuff, or a useless enchantment to push my black mana count up, justifying the 14 basic swamps. You also didn't say the fetches had to be able to find anything relevant sooo....