During your build step, you may reveal a card with Alternative Cost and printed build cost 9 or less from your hand to your opponent. If you do, remove Robida Colossus from the game instead of paying Alternative Cost for the revealed card.
Keywords
Alternative Cost
Alternative Cost: [cost]: A selective, static effect that means, "Instead of paying the build cost of this card, you may complete this card by paying the [cost] listed." Alternative Cost must be paid in full, if it is not possible to pay the [cost] completely, you can't complete the card. You must pay the [cost] in the order listed. Any ability that reduces the normal cost to complete a card does not reduce the [cost] in that card's Alternative Cost, unless the ability specifically says so.