Aside from (perhaps) Farmgirl, Dark Destroyer is the best Kozmo monster out right now.  Essential.  Staple card.  Every Kozmo deck needs to run 3.  
 
Forerunner was already an amazing card, but this takes everything to the next level.  Instead of 2800 ATK, you get 3000.  Instead of a passive LP gain effect, you can immediately destroy a monster (negging your opponent and opening the field up for an OTK).  The fact that Goodwitch/Farmgirl/Strawman/Wickedwitch allow you to summon this card from your hand at any time makes it even deadlier, since you can use Dark Destroyer's destruction effect as a way to disrupt a combo during the opponent's turn.  And, it replaces itself with a LV7 or lower monster (instead of a LV6 or lower).  This means you can summon Dark Destroyer, then replace it with a Forerunner, and then replace that Forerunner with a Sliprider, and you have a practically endless army of powerful monsters.  
 
But don't think for a second that this makes Forerunner in anyway obsolete (I'll still be copies of him too).  Since, as said earlier, you can use this card to summon Forerunner (and it's always nice to have some LP gaining in a Psychic deck as well).  If you thought 3 massive powerhouses that are difficult to take down and easy to OTK with were powerful enough, Dark Destroyer just takes the deck to the next level.
 
5/5

Kozmo Dark Destroyer, note first, we have a Machine, not a Psychic Monster.  Level 8, Dark, 3000 attack, which is just beautiful.  The 1800 defense is troublesome, probably the biggest vulnerability of this card.  
 
So what do we know about this card?  First, you're never going to Tribute for this card.  You'll Special Summon it via the removal effect of another low level Kozmo we saw earlier in this week, or outright Special Summon it, cause realistically we about never Tribute for anything.  
 
So when Normal or Special Summoned, you're able to Target (note Target) and destroy one Monster on the Field.  Note first, this is an optional effect, if this is the only Monster on the Field, it doesn't destroy itself via its own effect.  Additionally, Dark Destroyer cannot be Targeted by your opponent's card effects.
 
Finally, if sent to the Graveyard (only by Battle however, not via say non Targeted destruction) you can remove this card from play and Special Summon a Level 7 or lower Kozmo Monster from your Deck, as opposed to the Hand.  So he has selected protection for himself, a beastly attack, but the troubling part is that last bit.  With the 3000 attack, being destroyed by Battle might be difficult.  Great card for a good, rising Deck though.
 
Rating:  4/5 
Art:  5/5

Kozmo Dark Destroyer may be the best Machine-Type the “Kozmo” monsters can summon. DARK and Machine have support behind it, high ATK makes it a beatstick, and then it has a Zaborg effect whenever it hits the field. Topping it all off, it has internal protection against being targeted, this is a great Level 8.
 
With all the Special Summoning from the hand that “Kozmo” monsters do, it shouldn't be a problem getting Dark Destroyer on the field. Once there, it will stay for at least a few turns thanks to its protection ability. If it does leave, it trades itself out for any “Kozmo” Level 7 or lower. All “Kozmo” monsters aside from Dark Destroyer are below Level 7, giving you free reign on which monster to Special Summon from your deck. Use Kozmotown to get this card back and drop it back onto the field again using any of the non-Machine Kozmo monsters. Strawman can Special Summon it from the banished zone as a vanilla beatstick, and once its destroyed you'll get your search.
 
Run this in 3's, even if there were more Kozmo choices, this card is too good.
 
Advanced-4/5
Art-3/5
 
Until Next Time
KingofLullaby

The best in the business of badassery. We have come to Kozmo Dark Destroyer. The current money card at $130 on Amazon.com. Let's look at the raw stats. Dark Destroyer is a Level 8 Dark Machine-type Monster with 3000 Atk and 1800 Def. I am not sure why this isn't Kozmoll, but that doesn't matter. Kozmo matters. Kozmo support is still great and was not hit by the banlist at all. Level 8 is good, but 7 might have been better for XYZ purposes. Rank 8 is good too. Dark is good and opens some options with Allure of Darkness. Machine is of course great for multiple reasons, specifically Limiter Removal. Then we come to that beautifully high 3000 Atk. Good luck getting over that.

So if this card is Normal or Special Summoned, you can target to destroy 1 monster on the field. Optional and costless destruction is good.
Breakthrough Skill can't touch this effect because Dark Destroyer cannot be targeted by effects of the opponent. If it just so happens to be destroyed by battle or card effect, you can banish it to Special Summon any Level 7 or lower Kozmo monster from the deck. Every single one of these effects can be used multiple times per turn. I want to make a brief comparison to Black Luster Soldier - Envoy of the Beginning. BLS has high attack, an easy way of summoning itself, offensive and defensive effects, and  looks awesome. Dark Destroyer has all of that plus it can be Normal Summoned!
 
Score: 4.5/5 If only Honest could target this.
Art: 5/5 I have one from the Sneak Peak. I might not sell it because of the artwork.
-WarlockBlitz