Séance

• WWizards of the Coast2017-03-14
  Official Ruling
  The token doesn’t have haste (unless the card it’s copying has haste) and usually won’t be able to attack.
• WWizards of the Coast2017-03-14
  Official Ruling
  If the copied card has in its mana cost, X is considered to be 0.
• WWizards of the Coast2017-03-14
  Official Ruling
  The token copies exactly what was printed on the original card and nothing else. It doesn’t copy any information about the object the card was before it was put into your graveyard.
• WWizards of the Coast2017-03-14
  Official Ruling
  The token is a Spirit in addition to its other types. This is a copiable value of the token that other effects may copy.
• WWizards of the Coast2017-03-14
  Official Ruling
  The delayed triggered ability that exiles the token isn’t a characteristic of the token. If an effect such as populate copies the token, the new copy won’t be exiled.
• WWizards of the Coast2017-03-14
  Official Ruling
  If the card copied by the token had any “when [this permanent] enters the battlefield” abilities, then the token also has those abilities and will trigger them when it’s created. Similarly, any “as [this permanent] enters the battlefield” or “[this permanent] enters the battlefield with” abilities that the token has copied will also work.

Rulings via Scryfall