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.

Sliv-Mizzet, Hivemind · Mystery Booster Playtest Cards 2019 99/121

Sliv-Mizzet, Hivemind (Mystery Booster Playtest Cards 2019 99/121), Rare, Legendary Creature — Dragon Sliver. Market price $18.67, unchanged this week. Illustrated by Jeff Stewart. Prices are estimates from TCGPlayer and Cardmarket, not guaranteed values.

Weekly price history

Week	Market price
2026-W31	$24.41
2026-W32	$24.90
2026-W33	$26.66
2026-W34	$26.66
2026-W35	$26.66
2026-W36	$29.01
2026-W37	$18.83
2026-W38	$18.67
2026-W39	$18.67

Questions

How much is Sliv-Mizzet, Hivemind 99/121 worth?

Sliv-Mizzet, Hivemind from Mystery Booster Playtest Cards 2019 (99/121) has a market estimate of $18.67, unchanged this week. Prices are estimates from TCGPlayer and Cardmarket.

Is Sliv-Mizzet, Hivemind 99/121 rare?

It is a Rare from Mystery Booster Playtest Cards 2019, a 121-card set.

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