Look at the top X cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.
Flashback—, Exile X blue cards from your graveyard. (You may cast this card from your graveyard for its flashback cost, then exile it. You can't exile Flash of Insight to pay for its own flashback cost.)

Prevent all damage that would be dealt to this creature.
: Until end of turn, this creature loses "Prevent all damage that would be dealt to this creature." Any player may activate this ability.

, Sacrifice a creature: Search your library for a land card with a basic land type, put it onto the battlefield tapped, then shuffle.

Flying
As this creature enters, choose a nonland card name.
Spells with the chosen name can't be cast.
Activated abilities of sources with the chosen name can't be activated.

I. AM. TALKING! — Whenever The Eleventh Doctor deals combat damage to a player, you may exile a card from your hand with a number of time counters on it equal to its mana value. If it doesn't have suspend, it gains suspend.
: Target creature with power 3 or less can't be blocked this turn.

Flying, vigilance

Exile target creature. Its controller gains life equal to its power.

Whenever a player draws their second card during their turn, you draw a card.
Whenever a player casts their second spell during their turn, you create a 2/2 white Knight creature token.

When this creature enters, create two 3/3 colorless Phyrexian Golem artifact creature tokens.
Golem creatures you control have trample.

(: Add .)

You gain X life, where X is twice the damage dealt to you so far this turn by artifacts.

: Add .

Destroy all blocking creatures and all blocked creatures.

, : Draw a card. Activate only if you control three or more lands with the same name.

Haste

X target creatures can't be blocked this turn. Until end of turn, those creatures gain "Whenever this creature deals combat damage to a player, draw a card."

Each player may discard their hand and draw cards equal to the greatest mana value of a commander they own on the battlefield or in the command zone.

Whenever this creature attacks, destroy all other creatures.

When this creature enters, return target creature to its owner's hand.

Enchant creature (Target a creature as you cast this. This card enters attached to that creature.)
: Regenerate enchanted creature. (The next time that creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)