The hint is misleading here. FR "sauvage" may look like "savage", but it is a leap too far in this context. "Sauvage" means wild in this context: wild, untamed (animal); wild, remote (place); unauthorized (camping spot), unplanned (urban development). The use of "savage" is rather archaic here. If you want to say "savage", it would be féroce (to describe a person) or méchant to describe an animal.
That is a regular liaison in front of a vowel or a non-aspired H:
c'est un = Sè-T-un
c'est horrible = Sè-t-oribl
That liaison is optional but sounds much better.