We'll prolly have E4 outside of Gyms but I just wanted to post this up:
Chills in Combinations:
Say you run into a Chill + Protect combo staving off an attack that costs the Protect user 28 Energy.
One method would be to subtract the energy reduction from the chill directly from the combination's cost.
E.g. 28 - 12 = 16.
Now the 16 is multiplied by the 1.5x combo cost, to become 24.
This is the aggregate energy cost, because the Chill is factored into the move already. It has already had its intended effect, so it's not subtracting 24 from whatever the Pokemon's energy was +12, it's subtracting 24 from the Pokemon's current energy stock. E.g. The Pokemon doesn't get the Chill benefit twice: Once as a reduction of the combination's total energy cost and once as a full 12 EN Increase; it gets it once, which is either as a reduction in the attack or as an immediate increase to apply against the boosted cost of Protect. Otherwise there's never a time not to combine a Chill into any combination, since it would not only cause a negative energy cost, it'd also boost the energy again. (For example if Protect only cost 7 EN, under the calculation The Pokemon would gain 5 EN from the combo and then another 12 after the fact.)
An alternative calculation would be to apply the chill immediately (Pokemon's EN +12) and then multiply the cost to Protect (24) by 1.5x, which is 36. The first method is more efficient for the Pokemon using it, but as a rule I'd prefer the latter as it's both easier to follow and makes it only worthwhile for fairly inexpensive attacks.
Chills in Combinations:
Say you run into a Chill + Protect combo staving off an attack that costs the Protect user 28 Energy.
One method would be to subtract the energy reduction from the chill directly from the combination's cost.
E.g. 28 - 12 = 16.
Now the 16 is multiplied by the 1.5x combo cost, to become 24.
This is the aggregate energy cost, because the Chill is factored into the move already. It has already had its intended effect, so it's not subtracting 24 from whatever the Pokemon's energy was +12, it's subtracting 24 from the Pokemon's current energy stock. E.g. The Pokemon doesn't get the Chill benefit twice: Once as a reduction of the combination's total energy cost and once as a full 12 EN Increase; it gets it once, which is either as a reduction in the attack or as an immediate increase to apply against the boosted cost of Protect. Otherwise there's never a time not to combine a Chill into any combination, since it would not only cause a negative energy cost, it'd also boost the energy again. (For example if Protect only cost 7 EN, under the calculation The Pokemon would gain 5 EN from the combo and then another 12 after the fact.)
An alternative calculation would be to apply the chill immediately (Pokemon's EN +12) and then multiply the cost to Protect (24) by 1.5x, which is 36. The first method is more efficient for the Pokemon using it, but as a rule I'd prefer the latter as it's both easier to follow and makes it only worthwhile for fairly inexpensive attacks.