Charles Chaisson

"Literally everything in xenoanthropology is new and exciting."

Sam Kirk, Xenoanthropologist

Whenever an opponent casts a creature spell, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")

Officer

Rutherford, Upgraded Ensign

When Rutherford enters, look at the top six cards of your library. You may reveal an artifact card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.
Whenever you cast a Spacecraft spell, put a +1/+1 counter on target creature.

She's fluent in thirty-seven languages and infinitely more insightful than a universal translator.

Nyota Uhura, Communications

Hailing Frequencies — As Nyota Uhura enters, choose a number between 0 and 10.
Open a Channel — Whenever an opponent casts a spell with mana value equal to the chosen number, you draw a card.

Lieutenant Hikaru Sulu

Whenever Lieutenant Sulu becomes tapped, he explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)
{2}{U}: Target creature can't be blocked this turn.

In the Pale Moonlight

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Each opponent sacrifices a nontoken creature of their choice.
II — Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")
III — You may sacrifice an artifact or creature. If you do, create two 2/2 black Romulan creature tokens.

Excalbian Gamemaster

Strange new worlds — When this creature enters, create X 1/1 red Officer creature tokens, where X is the number of differently named lands you control.
Whenever this creature or another creature you control dies, put a +1/+1 counter on target creature you control.