Yu-Gi-Oh is the best strategy card game ever made. All others fail in compassion in how complex it is. In the over 8000 individual cards and growing, they all have interesting artwork on them.
1: Neo-spacian grandmole
When attacked on attacks it returns the oppent monster and it self to the hand. Or use it for level 3 xyz summon. This card has saved me many times.
http://yugioh.wikia.com/wiki/Neo-Spacian_Grand_Mole
2: Scrap-iron scarecrow
It’s perfect to save one monster a turn. Since it stays on the field when you use it.
http://yugioh.wikia.com/wiki/Scrap-Iron_Scarecrow
3: Thunder king rai-oh
Can be used for level 4 xyz. Negate drawing except at the start of your turn and you can tribute it to destroy a special summoned monster. Good for light decks.
http://yugioh.wikia.com/wiki/Thunder_King_Rai-Oh
4: Galaxy cyclone
Destory a face down spell or trap. Then you can banish the card in the graveyard to destroy a faceup.
http://yugioh.wikia.com/wiki/Galaxy_Cyclone
5: Anti-spell fragnence
Best defence to stop people from using pendulums.
http://yugioh.wikia.com/wiki/Anti-Spell_Fragrance
6: Jar of avarence
Best card to get spells and traps back to the deck. Return five cards back to your deck and draw a card.
http://yugioh.wikia.com/wiki/Jar_of_Avarice
7: Dandylion
No matter how you use it, when it goes to the graveyard, you summon 2 tokens. Perfect to use in a synchro summon.
http://yugioh.wikia.com/wiki/Dandylion
8: Wave-motion cannon
The ultimate burn card. Gains a counter every turn. Each counter is worth 1000lp. Use at any time to inflict massive damage directly.
http://yugioh.wikia.com/wiki/Wave-Motion_Cannon
9: Ghost of a grudge
8 cards need to be in your opponents graveyard. But then you can make all your opponents card’s attacks turn to zero.
http://yugioh.wikia.com/wiki/Ghost_of_a_Grudge
10: Greydle cobra
Steal your opponents monster that destroyed this monster. Or use it for level 3 xyz summon.
http://yugioh.wikia.com/wiki/Graydle_Cobra
11: Daigusto emral
Return three monsters from the graveyard to the deck and draw a card. Or if you use normal monsters, you can special summon one from the graveyard. Good in a wind deck.
http://yugioh.wikia.com/wiki/Daigusto_Emeral
12: Peropero cerperus
Good for level 3 xyz summons. Banish it in the graveyard to destroy a card.
http://yugioh.wikia.com/wiki/Peropero_Cerperus
13: Superheavy samurai bluebrawler
Cannot be destroyed by battle and good for level 4 xyz summons.
http://yugioh.wikia.com/wiki/Superheavy_Samurai_Blue_Brawler
14: Safe zone
Protects any monster from anything. Comes with some side effects.
http://yugioh.wikia.com/wiki/Safe_Zone
15: Ordeal of a traveller
The more cards in your hand, the greater chance your opponents cards will return to there hand.
http://yugioh.wikia.com/wiki/Ordeal_of_a_Traveler
16: Ghost orge and snow rabbit
Use for negating cards. Also a turner monster for synchros. Good defence for a turner card. Good in light and psychic decks.
http://yugioh.wikia.com/wiki/Ghost_Ogre_%26_Snow_Rabbit
17: Breaker the magicial warrior
Destroy a spell and trap card with it and then level 4 xyz summon. Good for dark decks.
http://yugioh.wikia.com/wiki/Breaker_the_Magical_Warrior
18: Supply squad
Combo with a monster effect when destroyed. Get that effect and draw one card.
http://yugioh.wikia.com/wiki/Supply_Squad
19: Soul charge
Summon five monsters to the field from the graveyard or less. Pay 1000 for each and cannot not attack that turn.
http://yugioh.wikia.com/wiki/Soul_Charge
20: Gold sarcopcus
Any card from your deck in two turns. Banish it for two turn.
http://yugioh.wikia.com/wiki/Gold_Sarcophagus
https://www.youtube.com/channel/UCatmc4McEx5tY_orMPPpXBQ