Sunhome, Boros Guild Hall

Sunhome, Boros Guild Hall enters the battlefield tapped.
Boros spells you cast cost {1} less to cast.
{t}: Add {c}.
{t}: Add {r}{w}. Spend this mana only to cast a
Boros spells or activate abilities of Boros spells.
That spells or abilities can't be countered.
{7},{t}: Search your library for a Boros spell,
reveal it and put it into your hand. Then shuffle
your library.