Xantcha, Sleeper Agent

This land enters tapped. T: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

You may look at the top card of your library any time. You may play lands and cast spells from the top of your library. If you cast a spell this way, pay life equal to its mana value rather than pay its mana cost. T, Sacrifice ten nonland permanents: Each opponent loses 10 life.

Flash Flying If an opponent would search a library, that player searches the top four cards of that library instead.

G: Exile target card from a graveyard. If it was a creature card, put a +1/+1 counter on this creature and you gain 1 life.

Haste Whenever this creature attacks, defending player reveals the top card of their library. If it's a land card, that player puts it into their hand.

Delve (Each card you exile from your graveyard while casting this spell pays for 1.) Look at the top seven cards of your library. Put two of them into your hand and the rest on the bottom of your library in any order.