Can I build a deck together with friends on TCGSwap?

Yes. Every deck on TCGSwap has a Collaboration Space. You can invite up to 5 friends; they can suggest card changes, discuss ideas, and playtest proposals. You review and apply suggestions before anything changes in your deck.

How does deck collaboration work?

It works like a pull request for your deck. Collaborators open the deck editor, make their proposed changes, and submit a suggestion with a note. You get notified, open the comparison view to see exactly what they changed, and choose to apply all, cherry-pick individual cards, or decline. Nothing changes in your deck until you approve it.

Can collaborators chat and discuss the deck?

Yes. The Collaboration Space has a shared group discussion thread for the whole deck, plus a per-suggestion Q&A thread for each proposal. You can @mention teammates and link specific cards inline.

Is collaborative deck building free?

Yes, collaboration is free for all TCGSwap users during beta. You can invite up to 5 collaborators per deck.

Does TCGSwap work for MTG, Pokémon, Yu-Gi-Oh and One Piece collaboration?

Yes. The Collaboration Space supports all four games — Magic: The Gathering, Pokémon TCG, Yu-Gi-Oh and One Piece. Format validation and card prices are included for each game.

Aegaion the Sea Castrum · Breakers of Shadow: Special Edition 10678778/4

Aegaion the Sea Castrum (Breakers of Shadow: Special Edition 10678778/4), Common. Market price $0.16, unchanged this week. Prices are estimates from TCGPlayer and Cardmarket, not guaranteed values.

2 Level 8 monsters During either player's turn: You can banish 1 random face-down monster from your opponent's Extra Deck, face-up, and if you do, this card's ATK becomes equal to the banished monster's. During either player's turn: You can detach 1 Xyz Material from this card, then target 1 of your opponent's banished Fusion, Synchro, or Xyz Monsters; return it to the Extra Deck, and if you do, destroy 1 monster your opponent controls with the same monster card type (Fusion, Synchro, or Xyz). You can only use each effect of "Aegaion the Sea Castrum" once per turn.

Weekly price history

Week	Market price
2026-W31	$0.18
2026-W32	$0.18
2026-W33	$0.18
2026-W34	$0.18
2026-W35	$0.18
2026-W36	$0.16
2026-W37	$0.15
2026-W38	$0.16
2026-W39	$0.16

Questions

How much is Aegaion the Sea Castrum 10678778/4 worth?

Aegaion the Sea Castrum from Breakers of Shadow: Special Edition (10678778/4) has a market estimate of $0.16, unchanged this week. Prices are estimates from TCGPlayer and Cardmarket.

Is Aegaion the Sea Castrum 10678778/4 rare?

It is a Common from Breakers of Shadow: Special Edition, a 4-card set.

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