One of the most powerful Yu-Gi-Oh! duelists of all time is without a doubt Seto Kaiba. Kaiba is extremely talented, and that is due in part to the craftsmanship of his deck. He always makes sure that he has a strong balance of monsters, spells, and traps.
Kaiba switches around his deck very often, and that includes his traps. The first few entries on this list are trap cards that he only used in one deck recipe, but always to great effect. As a note, all effects listed below are the anime versions of the cards.
Wish Of Final Effort
Wish of Final Effort is a very simple card that was only used in one arc by Kaiba, and it, very simply, restores life points based on the attack points of a monster that was just destroyed. Kaiba used this in the Waking the Dragons arc.
It's not all that good of a card, as life point restoring cards rarely are, but one sort of has to trust that Kaiba knows what he's doing when crafting a deck.
Tyrant Wing
Kaiba loves his dragons, especially when they're equipped with trap cards that boost their power.
Tyrant Wing gives the monster that it is equipped to 400 additional attack points, and allows it to attack twice in a battle phase if the opponent has a monster on their side of the field. With Tyrant Wing, Kaiba is essentially allowed to mow down his competition.
Flat Lv 4
Flat Lv 4 is a trap card that can only be activated when a monster is destroyed by battle. Once activated, both players can special summon a level four monster to their side of the field.
This is an incredibly useful card, especially because it doesn't specify which duelist has to lose a monster in order for it to be activated. As such, Kaiba can destroy an opposing monster and then summon a new one of his own. That's playing with power right there.
Pyramid Of Light
Pyramid of Light is a very, very simple card. Once activated, all God Cards that are on the field are removed from play. This isn't a good card for numerous reasons, but one of the main problems is that the second it is removed from the field, the God Cards are good to go again (those that haven't been removed).
It also sort of lets the Egyptian God of Death, Anubis, enter your brain and take over to destroy the pharaoh, an unfortunate side effect.
Return From The Different Dimension
Return from the Different Dimension, in the anime, allows the user to pay half of their life points in order to special summon as many of their monsters that have been removed from play as possible onto their side of the field.
While they must be removed from play once more at the end of the turn, it's a small price to pay for a card that can easily win the player the duel with ease.
Cloning
The rest of the cards on the list were used in multiple decks by Kaiba. Cloning is a very interesting card that can be activated in response to the opponent summoning a monster. The player is immediately allowed to summon a copy of that monster to their side of the field.
This is a useful effect that can be used in a variety of different ways, especially when it is used against powerful effect monsters.
Magical Trick Mirror
Magical Trick Mirror is a card that Kaiba often found himself using when he was in a tough spot. It can only be activated once the opponent declares an attack.
In response, the player is allowed to use a spell card from their opponent's graveyard. Kaiba famously used this card in the KC Grand Championship arc to skip Zigfried's battle phase with Mischief of the Time Goddess in their very close duel.
Ring Of Destruction
Ring of Destruction is a trap card that allows the player to select one monster on the field and destroy it. In addition, both players lose life points equal to the monster's attack points.
This is a nice card to have in the back pocket because it's some solid removal along with a bit of damage. It is also notable because it is one of the few cards in the game that can cause a tie, which is a very rare occurrence.
Attack Guidance Armor
Attack Guidance Armor is a simple card that, when activated, allows the player to switch the target of an attack to any monster on the field that they choose.
This can come in handy as it can easily allow the player to force the opponent to destroy one of their own monsters, or just take out one of their less valuable monsters.
Crush Card Virus
Crush Card Virus is easily Kaiba's ace trap, he uses it in almost every single version of his deck. Once a dark monster on your side of the field with less than 1000 attack points is destroyed, the opponent must destroy every card on their side of the field and in their hand with over 1500 attack points.
This card had different effects depending on what point in the anime it was used, but it was a mainstay in Kaiba's deck that he never left out of the rotation.