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.

Seaking · Ruby & Sapphire 21/109

Seaking (Ruby & Sapphire 21/109), Rare, Stage1, 70 HP. Market price €0.67, unchanged this week. Illustrated by Hajime Kusajima. Prices are estimates from TCGPlayer and Cardmarket, not guaranteed values.

Card text

Water Arrow — Choose 1 of your opponent's Pokémon. This attack does 20 damage to that Pokémon. (Don't apply Weakness and Resistance for Benched Pokémon.)
Fast Stream 30 — Move 1 Energy card attached to the Defending Pokémon to the other Defending Pokémon. (Ignore this effect if your opponent has only 1 Defending Pokémon.)

Weekly price history

Week	Market price
2026-W31	€0.56
2026-W32	€0.60
2026-W33	€0.60
2026-W34	€0.61
2026-W35	€0.60
2026-W36	€0.62
2026-W37	€0.66
2026-W38	€0.67
2026-W39	€0.67

Printings & variants

Normal — $1.00
Reverse Holo — $16.36

Questions

How much is Seaking 21/109 worth?

Seaking from Ruby & Sapphire (21/109) has a market estimate of €0.67, unchanged this week. Prices are estimates from TCGPlayer and Cardmarket.

Is Seaking 21/109 rare?

It is a Rare from Ruby & Sapphire, a 109-card set.

Is Seaking 21/109 tournament legal?

Seaking 21/109 has rotated out of the current formats.

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