If you have "Level Eater" in your Graveyard, you can reduce the Level of "Quickdraw" by 1 and Special Summon "Level Eater" from your Graveyard. By using "Quickdraw" with "Cosmic Compass", "Level Eater" and two "Compass Tokens" to Synchro Summon "Destroyer", you can destroy a total of 4 cards on the field.
"Quillbolt Hedgehog" must be in the Graveyard first. Then Normal Summon "Marauding Captain", and then use its effect to Special Summon "Junk Synchron" from your hand to the field. Then, Special Summon "Quillbolt" from the Graveyard and Synchro Summon "Junk Destroyer", and use its effect to destroy up to 2 cards on the field.
When coupled with "Royal Decree", the Synchro Summon of this card (and its effect) will not be negated by irritating traps such as "Solemn Warning", or be destroyed by Traps such as "Bottomless Trap Hole", allowing you to destroy your opponents cards for an open field AND "Geartown" to Special Summon "Ancient Gear Gadjiltron Dragon" for a possible 5600 damage (the reason why destroying your own "Geartown" with this card's effect won't force "Geartown" to miss timing is because this card destroys all cards that it targets at the same time).
The max number of cards you can destroy is 4, but keep in mind that you have to forget using stronger monsters until you Synchro Summon this card.
If you use "Synchro Material" you can destroy 5 monsters, essentially getting rid of 6 cards on the field.
For this combo you will need to have "Debris Dragon", "Dandylion" and "Quickdraw Synchron" in your hand ("Dandylion" can be in the Graveyard, given that you already have 2 Tokens on the field).
Discard a monster for the effect of "Quickdraw" in order to Special Summon it, Normal Summon "Debris Dragon", use it to Special Summon "Dandylion" from the Graveyard; Use "Debris" to Synchro Summon for "Stardust Dragon" (or any Level 8 DragonSynchro Monster) with "Dandylion" and 1 Token, by then you should already have 3 Level 1 Tokens on your field, use "Quickdraw" and the 3 Tokens to Synchro Summon "Junk Destroyer" to destroy 3 cards on the field.
Another way to Synchro Summon this card, is to send "Quillbolt Hedgehog" from your hand to the Graveyard, to Special Summon "Quickdraw Synchron" from your hand. Then activate the effect of "Quillbolt", and Special Summon it. Then Normal Summon in any Level 1 Monster Card, and tune them together to Synchro Summon "Junk Destroyer". Its effect allows you to destroy 2 cards on the field.
Special Summon "Quickdraw" and "Level Eater" then Normal Summon "Dark Spider" and use the effect of "Dark Spider" to increase the Level of "Level Eater".
Have at least "Junk Synchron" and a Level 3 Tuner monster. First, you need to have a Level 2 non-Tuner monster ("Quillbolt Hedgehog" would work) in your Graveyard. Special Summon it back on the field with the effect of "Junk Synchron", and use that to Synchro Summon "X-Saber Wayne". "Wayne" allows you to Summon a Level 4 or lower Warrior-Type monster on the field; Summon your Level 3 Tuner. Then, tune both of those to Summon "Junk Destroyer". Note that you can only destroy one card using this combo.
The most effective tactic when Synchro Summoning this card is to use "Scapegoat" prior to your opponent's turn, followed by Summoning "Quickdraw Synchron" during your turn. This will give you 3 non-Tuners instantly (plus 1 extra "Goat Token"), thus you will destroy 3 cards and have a 2600 ATK monster.
Use "De-Synchro" to destroy twice the number of cards.
First, use "One for One" by sending "Quillbolt Hedgehog" to the Graveyard to Special Summon "Tuningware". Then discard "Level Eater" and Special Summon "Quickdraw Synchron". Use the effect of "Quillbolt" to Special Summon itself. Then use the effect of "Level Eater" from the Graveyard to Special Summon itself, reducing the Level of "Quickdraw" to 4. Draw 1 card and destroy 3 cards on the field.
When you Summon "Junk Synchron", resurrect "Tuningware" then use either "Inferno Reckless Summon" or "Machine Duplication" to Summon two more "Tuningware". Thus, when you Synchro Summon "Junk Destroyer", not only will you destroy 3 cards, you will also draw three cards.
You can use three copies of "Darksea Rescue" to assist the same strategy, provided that another monster or effect makes up for the Level differences between "Darksea Rescue" and "Tuningware". Recall as well that another monster used for such purpose will end up assisting "Destroyer".
Use the repeatedly suggested "Level Eater"/"Quickdraw Synchron" strategy to Special Summon both, then use "Inferno Reckless Summon" for more copies of "Level Eater". Normal Summon a Level 1 monster or use "One for One", so you can Synchro Summon this card and destroy four of your opponent's cards.
If you want, continue by Special Summoning the three "Level Eaters" from the Graveyard for a Tribute fodder if you haven't Normal Summoned yet.
Summon "Darksea Rescue", then use "Machine Duplication" to Special Summon two more. Special Summon "Quickdraw Synchron" by Tributing a "Level Eater", later bringing back "Level Eater" and Synchro. Destroy 4 cards and draw 3.
In combination with "The Immortal Bushi" you can Synchro Summon this card more easily. After Summoning "Junk Synchron" and Special Summoning a Level 2 monster from the Graveyard, you can destroy 2 cards.
Use 3 copies of "Level Eater" on a Level 7 or higher monster, along with "Quickdraw Synchron", to easily Synchro Summon this card while being able to destroy more cards.
Another combo to rid your opponents field of 4 cards is by using "Scapegoat" at the end of their turn. Summon "Junk Synchron" and activate "Synchro Boost" to raise the Level of "Junk Synchron". Tune all 5 of these monsters for a way to bring "Junk Destroyer" onto the field.
This also works for a one turn Summon, and can destroy 3 cards. You need "Junk Synchron" and "Quillbolt Hedgehog" in the Graveyard, and "Synchron Explorer" and "Turbo Booster" in hand. Summon "Explorer", sending "Booster" out there with it. Next, use the effect of "Explorer" to bring back "Junk Synchron". Though the effect of "Junk Synchron" is negated, it is still a Tuner, which means "Quillbolt" is still coming back. Now Synchro for "Junk Destroyer". This will also make "Synchro Strike" more potent.