Razz, Walking Boiler

{1}{u}: The next instant or sorcery spell you cast this turn costs {r} less to cast.
{1}{r}: The next instant or sorcery spell you cast this turn costs {u} less to cast.
Whenever you cast a spell, if no mana was spent
to cast it, Razz, Walking Boiler deals damage equal to its converted mana cost to target player.