If I'm playing Wrecking Ogre, a spell with Bloodrush 3RR and have a Ruby Medallion out (all red spells cost 1 less to play) does this also affect the Bloodrush?
In the same vein, can I use Smokebraider's ability ({T}: Add two mana in any combination of colors to your mana pool. Spend this mana only to cast Elemental spells or activate abilities of Elementals) to pay the Bloodrush on a Scorchwalker (which is an elemental creature)?
Bloodrush is an activated ability that you can use from your hand. You are not casting the card when you use it. Thus, bloodrush is unaffected by any effects that modify casting costs.
Cards that affect abilities, however, do affect bloodrush — as long as they can affect cards in your hand. E.g. Suppression Field will make all bloodrush cards more expensive to activate because it doesn't limit the scope of "activated abilities," but Training Grounds does not modify bloodrush costs because it is scoped to creatures you control (not creatures cards in your hand).
In Smokebraider's case, the card specifies "abilities of Elementals," which means permanents with the Elemental type. This is clarified in the Oracle text:
10/1/2007 The mana can't be spent to activate activated abilities of Elemental sources that aren't on the battlefield.
No and no.
Bloodrush is an activated ability [CR 207.2c, 112.3b]. It's not a spell [CR 111.1, 111.1a].
Ruby Medallion does not reduce the cost of Wrecking Ogre's or Scorchwalker's Bloodrush ability.
Bloodrush can only be activated from someone's hand (since discarding it is part of the activation cost) [CR 112.6i].
Since Smokebraider's mana can only be used for the activated abilities of Elementals (i.e. Elemental permanents (i.e. Elemental cards and tokens on the battlefield)) [CR 109.2], it can't be used to activate a Bloodrush ability.
Mana from Smokebraider ability cannot be used to activate Scorchwalker's Bloodrush ability.
The rules referenced above:
207.2c An ability word appears in italics at the beginning of some abilities. Ability words are similar to keywords in that they tie together cards that have similar functionality, but they have no special rules meaning and no individual entries in the Comprehensive Rules. The ability words are bloodrush, [...].
112.3b Activated abilities have a cost and an effect. They are written as “[Cost]: [Effect.] [Activation instructions (if any).]” [...]
111.1. A spell is a card on the stack. [...]
111.1a A copy of a spell is also a spell [...].
112.6i An object’s activated ability that has a cost that can’t be paid while the object is on the battlefield functions from any zone in which its cost can be paid.
109.2. If a spell or ability uses a description of an object that includes a card type or subtype, but doesn’t include the word “card,” “spell,” “source,” or “scheme,” it means a permanent of that card type or subtype on the battlefield.
