Jackal Lockdown
Jackal Lockdown is an old but still somewhat well-known deck, based on a similar draw lock as the infamous Yata-Garasu Lockdown. In this case, the lock is created by emptying the opponent's hand and destroying one of their monsters with "Mystical Knight of Jackal", returning it to the top of their deck to be drawn next turn. If the destroyed monster is one they can summon, next turn, they can either protect themselves by summoning the monster to have it be destroyed by battle again, thus ensuring the loop continues, or hold onto the monster in the hopes of freeing up their draw for a needed card next turn, in which case they've left themselves open a direct attack.
Since draw and hand control is crucial to the success of this lock, using cards that can empty the opponent's hand and keep them from drawing cards outside of their draw phase is a necessity; "Protector of the Sanctuary", "Deck Lockdown", "X-Saber Airbellum", "Spirit Reaper", "Trap Dustshoot", Goe Goe the Gallant Ninja, etc. are all good cards to have for this purpose. Many players also put in "Winged Sage Falcos", "Mystic Swordsman LV6" and now "X-Saber Uruz" as supplements for "Mystical Knight of Jackal", as "Mystical Knight" is a 2-Tribute monster that can be difficult to summon; if you use these cards, "Burden of the Mighty" is a good choice for helping you destroy the opponent's monsters through battle. Equipping "Jackal" with "Wicked-Breaking Flamberge - Baou" will negate the effects of monsters he destroys as he bounces them to the opponent's Deck in addition to increasing his ATK to 3200.
Other means of field control are good to continue the loop but aren't necessary; except for cards such as "Dimensional Prison" or "Mirror Force" that would stop your attacks before they do anything, or monsters such as "Shiba-Warrior Taro" or "Marshmallon", that prevent their monster(s) from being destroyed by battle, clearing the field before attacking isn't all that necessary to start or continue the loop. "Scrap-Iron Scarecrow" blocks the attacks of "Jackal" once per turn, thus getting rid of this lock. You can even leave more than one monster on the opponent's side of the field, so long as none of them are Tuner monsters or are stronger than yours. The key is to make sure that your opponent does not have any cards in their hand when the loop gets started, thereby ensuring they're forced to replay the same card over and over again.
