{T}: Add {C}. Whenever you cast a colorless spell with mana value 7 or greater, you may sacrifice Sanctum of Ugin. If you do, search your library for a colorless creature card, reveal it, put it into your hand, then shuffle.
For hundreds of years Ugin slept, encased in the cocoon of stone and magic Sarkhan had created using a shard of a Zendikari hedron. As Ugin lay dormant, his spectral guardians kept vigil.
Ugin's Conjurant enters with X +1/+1 counters on it. If damage would be dealt to Ugin's Conjurant while it has a +1/+1 counter on it, prevent that damage and remove that many +1/+1 counters from Ugin's Conjurant.
If a player would begin an extra turn, that player skips that turn instead. If Ugin's Nexus would be put into a graveyard from the battlefield, instead exile it and take an extra turn after this one.
Colorless spells you cast cost {2} less to cast. [+1]: Exile the top card of your library face down and look at it. Create a 2/2 colorless Spirit creature token. When that token leaves the battlefield, put the exiled card into your hand. [–3]: Destroy target permanent that's one or more colors.
[+2]: Ugin, the Spirit Dragon deals 3 damage to any target. [–X]: Exile each permanent with mana value X or less that's one or more colors. [–10]: You gain 7 life, draw seven cards, then put up to seven permanent cards from your hand onto the battlefield.