Titans' Nest

Text:

At the beginning of your upkeep, surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)
Exile a card from your graveyard: Add {C}. Spend this mana only to cast a spell that's one or more colors without in its mana cost.

Rulings:

• 4/17/2020 If you don’t put the card you look at into your graveyard, it remains on top of your library. You’ll draw it during your draw step unless something else moves it.
• 4/17/2020 Mana produced by Titans’ Nest can be used to cast a spell that has <img src="/Handlers/Image.ashx?size=small&amp;name=X&amp;type=symbol" alt="Variable Colorless" align="absbottom" /> in an additional or alternative cost.