Solar Flare Dragon
Group: Pyro/Effect
Type: Fire
Level: 4
Atk: 1500
Def: 1000
As long as this card is in the Deckmaster position, if multiple Fire-attribute monsters are on your side of the field, you may change the target of your opponent's attacks to any of your other Fire-attribute monsters. Tribute a Pyro sub-type monster to inflict 500 points of damage to your opponent's life points.

Goblin King
Group: Fiend/Effect
Type: Dark
Level: 1
Atk: 0
Def: 0
Once per turn you may search for any card with "Goblin" in its name and add it to your hand. Increase this card's ATK by 600 for each card with "Goblin" in its name in your Graveyard.

Arsenal Summoner
Group: Spellcaster/Effect
Type: Wind
Level: 4
Atk: 1600
Def: 1600
As long as this card is in the Deckmaster position, any card with "Guardian" in their name may be normal summoned, special summoned, or flip summoned without needing an equip card on the field by paying 500 LP (the summoning must still be otherwise legal). You may pay 500 LP to change the target of any Equip cards on your side of the field to another monster on your side of the field (this must be done during Main Phase 1).

Two AST ideas I've been playing around with, and one because I really think a good Guardian DM is needed. :)