[hider=One of my favourite archtypes, now with proposed custom card support :D!]
Name: Lesser Maju Garzett 
Level/rank: 5
Attribute: Dark
Monster Type(s): Fiend
Effect: If your opponent controls a monster and you control no monsters, you can Normal Summon/Set this card without Tributing. During the turn this card was Normal Summoned, you can Normal Summon 1 monster in addition to your Normal Summon/Set. (You can only gain this effect once per turn.)
ATK/DEF 2000/0

Name: Perfectly Ultimate Maju Garzett 
Level/rank: 12
Attribute: Dark
Monster Type(s): Fiend
Effect: You can Tribute 3 monsters or 1 monster to Tribute Summon (but not Set) this card. This card gains ATK equal to the combined Levels that all monsters Tributed for its Tribute Summon had on the field x 300. When this card is Tribute Summoned by Tributing at least 1 "Maju" monster: You can activate any of these effects, and resolve in sequence, up to the number of monsters Tributed for its Summon;
● Return all other Monsters on the field to the hand.
● Return all Spell and Trap Cards on the field to the hand.
● Send all cards in both players' hands to the Graveyard.
ATK/DEF 0/0

Name: Phantasmal Maju Garzett
Level/rank: 9
Attribute: Dark
Monster Type(s): Fiend, Tuner
Effect: This card cannot be Normal Summoned or Set. If a face-up "Maju" monster you control is sent to your Graveyard while this card is in your hand or graveyard: Special Summon this card. If Summoned this way, banish it when it leaves the field. This card's ATK is each equal to the number of cards your opponent controls and in their hand x 500. 
ATK/DEF ?/0

Name: Unstable Maju Garzett
Level/rank: 4
Attribute: Dark
Monster Type(s): Fiend
Effect: This card cannot be Normal Summoned or Set.  Must be Special Summoned by its own effect, and cannot be Special Summoned by other ways. Requires 2 Tributes from either side of the field to Special Summon to that side of the field (cannot be Normal Set), then shift control to this card's owner during the End Phase of the next turn. If Summoned this way, this card's controller Targets 1 Monster in the Graveyard that was Tributed; this card's name becomes that target's name, and this card gains that target's effects (if any). This card's ATK is each equal to the number of cards in your graveyard x 300. 
ATK/DEF ?/0

Name: Gren Maju Da Cyaz
Level/rank: 2
Attribute: Water
Monster Type(s): Fiend, Tuner
Effect: This card cannot be Normal Summoned or Set. Must be Special Summoned by its own effect, and cannot be Special Summoned by other ways. When an opponent's monster declares an attack: You can Special Summon this card from your hand, then make your opponent's attack a direct attack instead. If Summoned this way, banish it when it leaves the field. This card's ATK is each equal to half the opponent's Life Points.
ATK/DEF ?/0

Name: Call of the Maju
Spell Type: Continuous
Effect: If your opponent controls a monster and you control no monsters: you can Banish 1 "Maju" card from your Deck, Face-up; apply 1 of these effects. You cannot Summon any monsters during the turn you activate this effect, except "Maju" monsters. You can only activate 1 "Call of the Maju" effect per turn, and only once during that turn.
● Add 1 "Maju" Monster card from your deck or graveyard to your hand.
● Once during per turn, if you would Tribute a monster(s), you can Tribute 1 monster your opponent controls as if you controlled it.

Name: Evolved Maju Garzett 
Level/rank: (none)
Attribute: Light
Monster Type(s): Fiend, XYZ
Effect: 2 "Maju" Monsters with the same level
(This card's original Rank is always treated as 1.)
This card's effects can only be applied/resolved while it has Xyz Material. Cannot be destroyed by battle, and neither player takes any battle damage from attacks involving this card. At the end of the Damage Step, if this card battled an opponent's monster: attach that monster to this card as a face-up Xyz Material. If this face-up card on the field would be destroyed by a card effect, you can detach 1 Xyz Material from this card instead. This card's ATK is equal to the number of XYZ material attached to it x 1000.
ATK/DEF ?/0

Name: Gren Maju Da Fuzh 
Level/rank: 11
Attribute: Earth
Monster Type(s): Fiend, Fusion
Effect: 2 or more "Maju" Monsters
Must be either Fusion Summoned, or Special Summoned by sending the above cards you control to the Graveyard (in which case you do not use "Polymerization"), and cannot be Special Summoned by other ways. Cannot be destroyed by battle. Each turn, this card can attack your opponent's monsters a number of times equal to the number of Fusion Material Monsters used for its Fusion Summon. This Card's ATK is equal to the number of Fusion Material Monsters used for its Fusion Summon x 700
ATK/DEF ?/0

Name: Gren Maju Da Zink
Level/rank: None
Attribute: Wind
Monster Type(s): Fiend, Synchro
Effect:(This card's original Level is always treated as 10.) Cannot be Synchro Summoned. Must be Special Summoned (from your Extra Deck) by sending 2 "Maju" monsters you control to the Graveyard (1 Tuner and 1 non-Tuner), and cannot be Special Summoned by other ways. Cannot be destroyed by battle, and neither player takes any battle damage from attacks involving this card. At the start of the Damage Step, if this card battles a Monster: you can equip 1 face-up monster your opponent controls to this card, except the battling monster. This Card's ATK is equal to the combined original ATK of the monsters equipped to it by this effect.
ATK/DEF ?/0
[/hider]