My current YGO main deck

[Ami Mizuno]

I'm nut sure about this deck, but it here it is..

Monsters:

Familiar-Possessed - Hiita
Familiar-Possessed - Eria
Familiar-Possessed - Aussa
Gemini Elf x2
Princess of Tsurugi
Mask of Darkness
Winged Kuriboh x2
Marshmallon
Spear Dragon x2
A-Team: Trap Disposal Unit
Sasuke Samurai
Obnoxious Celtic Guard
Master Kyonshee
Buster Blader
Cyber Tutu
Cyber-Tech Alligator
Cyber Gymnast x2
Red-Eyes B. Dragon
Wolf Axwielder
Summoned Skull
Mirage Dragon

Magic/Spells:

Card Destruction
Ookazi
Dian Keto, The Cure Master
Fissure
Premature Burial
Tribute to the Doomed x2
Nobleman of Crossout
Dark Factory of Mass Production x2
Lightning Vortex x2

Traps:

Trap Jammer x2
Negate Attack x2
Sakuretsu Armor x2
Compulsory Evacuation Device
Magic Cylinder
Legacy of Yata-Garasu
Waboku
Cemetary Bomb
Ojama Trio
Call of the Haunted

Total: 50 cards

I haven't really messed with my deck in a few months.. But yeah.. Please give full criticism so I'll know what to improve on..

 

[ソラ]

Take Out 1 Winged Kuriboh, and put in Kuriboh. Other than that, I like your deck.

 

[Gymnotide]

Monsters:

Familiar-Possessed - Hiita
Familiar-Possessed - Eria
Familiar-Possessed - Aussa
Gemini Elf x2
Princess of Tsurugi
Mask of Darkness
Winged Kuriboh x2
Marshmallon
Spear Dragon x2
A-Team: Trap Disposal Unit
Sasuke Samurai
Obnoxious Celtic Guard
Master Kyonshee
Buster Blader
Cyber Tutu
Cyber-Tech Alligator
Cyber Gymnast x2
Red-Eyes B. Dragon
Wolf Axwielder
Summoned Skull
Mirage Dragon

Magic/Spells:

Card Destruction
Ookazi
Dian Keto, The Cure Master
Fissure
Premature Burial
Tribute to the Doomed x2
Nobleman of Crossout
Dark Factory of Mass Production x2
Lightning Vortex x2

Traps:

Trap Jammer x2
Negate Attack x2
Sakuretsu Armor x2
Compulsory Evacuation Device
Magic Cylinder
Legacy of Yata-Garasu
Waboku
Cemetary Bomb
Ojama Trio
Call of the Haunted

The deck with the fewer amount of cards will usually win because their deck cycles better and it is easier to get combos out. Needless to say, you'll need to cut down on some cards. Also, I'm not seeing much here that can really win a game other than brute force, which doesn't work so well anymore.

Cards listed below need to change.

• Familiar-Possessed - Eria - Since you're not using WATER-type monsters, you're better off using Wynn since you have more WIND-types. These cards in general aren't so hot, but they're strong, easily Special Summoned, and gain piercing under certain conditions. They're iffy because of the small amount of each type you use.
• Princess of Tsurugi - This card doesn't belong in this deck. It's more suited to a burn-type deck and often won't offer you any more protection or offense than your other cards.
• Winged Kuriboh - Unnecessary, really.
• A-Team: Trap Disposal Unit - It's weak, lacks the element of surprise and is a waste of a Summon at most times. Sure, it can protect you from a single trap, but often your foe will be able to get around it easily.
• Sasuke Samurai - Mystic Swordsman LV2 is stronger.
• Master Kyonshee / Wolf Axweilder - Its stats aren't optimal. You'd do better with a card like Regenerating Mummy, but that's also pretty unnecessary.
• Buster Blader / Cyber Tutu / Red Eyes B. Dragon - Not worth it, really.
• Ookazi / Dian Keto the Cure Master - Weak cards, limited use. Poison of the Old Man beats both, but that card sucks as well.
• Premature Burial - Replace with Monster Reborn.
• Legacy of Yata-Garasu - Deck-thinning is unnecessary with a deck this big. Draw 2 cards effect is situational.
• Cemetery Bomb - Weak card except when used with Needle Worms or something of the sort. By the time it's potent enough to do a big amount of damage, you'll already have a Judgment Dragon or two in your face.
• Call of the Haunted - Banned.
• Sakuretsu Armor - Replace one with a Mirror Force.

A lot of the other cards are good on their own, but lack synergy with the rest of the deck.

You'll also want to consider including
-- Smashing Ground
-- Heavy Storm
-- Mystical Space Typhoon
-- Dust Tornado
-- Torrential Tribute
-- Jinzo / Royal Decree if you cut down your trap count
-- Brain Control
, etc.