According to TGOT you can play as many attachments as you want now! Here's my take on a deck
abusing the Kings of the Sea Viserys.
Expect to have terrible draws and setups. Definitively a Shagga deck.
House (1) House Targaryen (Core) x1
Agenda (4) The Maester's Path (GotC) x1 Bronze Link (FtC) x1 Pale Steel Link (FtC) x1 Valyrian Steel Link (HtS) x1
Character (27) Viserys Targaryen (KotS) x3 Kraznys mo Nakloz (TRS) x1 Red Warlock (ASoS) x3 Advisor to the Crown (QoD) x2 Ser Jorah Mormont (PotS) x1 Herald of the East (SB) x2 Initiate of the Citadel (QoD) x3 White Hatchling (AKitN) x1 Green Hatchling (TWH) x1 Black Hatchling (DB) x1 Samwell Tarly (TRS) x3 Carrion Bird (ASoS) x3 Brown Ben Plumm (Core) x1 Refugee of the Plains (RoW) x1 Gilly (RoW) x1 Location (17) Lady Daenerys's Chambers (Core) x1 Pentos (EB) x2 Xaro's Home (Core) x3 Meereen Tourney Grounds (ODG) x2 Khal Drogo's Tent (Core) x1 Eastern Fiefdoms (QoD) x3 Summer Sea (PotS) x3 Myrish Villa (QoD) x1 The Inn of the Kneeling Man (FtC) x1 Event (0) Attachment (19) Black Raven (ASoS) x3 Unburnt (QoD) x3 Aegon's Blade (Core) x1 Hrakkar Pelt (RotO) x2 Rich Lands and a Keep (LotR) x3 Court Advisor (PotS) x3 Bodyguard (Core) x1 Apprentice Collar (GotC) x3 Plot (7) Spending the Winter Stores (QoD) x1 At the Gates (GotC) x1 A Time for Ravens (ACoS) x1 The Power of Blood (Core) x2 The Promise of Victory (KotS) x1 Wildfire Assault (Core) x1 So you are hoping to draw cap every turn with the attachments that let you draw a card and Xaro's Home.
Use Spending to get a Rich Lands for Viserys to make Power of Blood a live play.
Put chains on initiate then replay onto Viserys.