T-100, Thief of Darkness
Monster: Machine/Effect/Special Summon only
Atrribute: Dark, seven stars
Atk: 2000, Def: 1800
By either discarding four cards in your hand or paying 1500 Life Points, you can take one card from your opponent's hand or field, and use it until it's destroyed. You can view the opponent's hand by either discarding three cards or paying 1000 Life Points. Once the controlled card is destroyed, send it to the top of the opponent's deck. The opponent's deck is then shuffled.
...Meh.
T-101, Robot of the Flame
Monster: Machine/Effect/Special Summon only
Atrribute: Fire, six stars
Atk: 1800, Def: 1200
By tributing up to five monsters from your side of the field or your hand, you can activate it's effect. Directly inflict 700 damage times the number of monsters tributed. If an effect or spell/trap card negates this, increase the attack or defence of this monster by 1000 points.
Same.
T-102, Robotic Master of Wind
Monster: Machine/Effect/Special Summon
Atrribute: Wind, seven stars.
Atk: 1600 Def: 2400
Flip: Once this creature is flipped, summon up to four wind, machine, or winged beast cards from your deck. In return, remove one card in your deck with an attack more than 2000 from play (if there isn't a card with an attack that high, pay 1000 life points). Put the card back into face-down defence position. This effect can only be activated every 5 turns.
Broken, and yes, will be banned almost immediately.
T-103, Aquatic Wizard
Monster: Machine/Effect/Special Summon
Atrribute: Water, six stars.
Atk: 1700 Def: 2000
By tributing three machine monsters (and removing one from play) you can remove from play up to two cards cards on your opponent's side of the field, or hand.
...Okay.
Robotic Tournament
Spell
Draw up to 8 machine cards from your deck (the number of drawn cards has to be even). Give half and keep 4. All current monsters on the field will be then put into the graveyard. Once your given set of machine cards are destroyed, then you may put another card down on the field again.
"Give" half?
And...the last sentence makes little sense, to be blunt.
Factory of Power
Spell
Pay 500 life points to activate this. Remove one machine card from play, to special summon all cards with "T-10x" in their name. X is a variable.
Removed from where?
And you can cover the variable by just saying "monster whose name starts with 'T-10'". Better-sounding, that's all.
Malfunction
Trap
All cards on the opponent's side of the field lose 150 ATK and DEF for each time a coin is flipped out of four times.
There's already a card named Malfunction.
Evasion Microchip
Trap
This card can only be used when your opponent targets a monster. The selected monster can evade the attack.
..."Targets the monster"? With an attack or effect?
Insert Machinery Into Group
Spell
For three turns, all monsters in your hand and the field become machine types.
Bettter name, please? No offense, but it just doesn't fit...
Metal Hurricane
Trap/Equip
Tribute upto three monsters in your hand in order to destroy a monster on your opponent's side of the field. Equip this afterwards to a machine card to add 250 ATK or DEF per monster destroyed/tributed.
Usually monsters are discarded from the hand, but otherwise okay.