This page contains the reasoning behind the KirriCorp League's errata on the card Searing Wave, shown below in its original form.

Name: Searing Wave
Type: Spell
Civilization: Fire
Cost: 5
Rules Text: Destroy all your opponent's creatures that have power 3000 or less. Choose one of your shields and put it into your graveyard.
Mana Number: 1
Set: Rampage of the Super Warriors

As with all KC errata, justification of this argument relies on the semi-rigid card costing system given within Duel Masters. The relevant aspects of the cost system are shown, with examples, in the following data. It is assumed that all fire spell cards should have equal cost-to-destructive-power ratios until cost 6. After this, they gain twice as much destructive power for every point of cost added.

Ability: To destroy a creature of hypothetical power 0000 that is somehow not destroyed due to this.
Cost: The card itself, once the spell is cast.

Ability: Conditional removal of a creature from the battle zone to the graveyard.
Cost: X, where X000 or less is the power of the creature.
Reference: Crimson Hammer, Spastic Missile, Tornado Flame(+1 Cost for Shield Trigger)

Searing Wave is a very strangely constructed card. When one has no shields, it may still be cast, making the second aspect of its cost a non-issue. When there is only one opposing creature that it will destroy, it may still be cast, costing 2 more than it 'should', and costing a shield also.

When there are two opposing creatures, it may be cast for what is fundamentally a fair cost. Two creatures are destroyed, and the card is lost, as well as another card. Basically the same as casting Spastic Missile twice, but for one less mana and requiring one less card in hand.

When there are three opposing creatures, it may be cast and have the effect of three Spastic Missile, but for four less mana and requiring two less cards in hand, and sending one less card to grave (also requiring less Fire mana available). Note that if even one opposing card has only 2000 power, the spell will have the same effect as the Apocalypse Vise, for two less mana (this is not in itself unfair, just a note).

If all 3 of the opposing cards have 3000 power, the spell can do what Apocalypse Vise cannot, still, for two less mana, but there is at least the sacrifice of a shield.

As the number of opposing creatures rises, so does the effect of Searing Wave if these creatures have less than 3000 power. As of now, in the Duel Masters Civilizations program, there are 713 non-evolution creatures. Of those, 433 creatures have less than 3000 power.

Of those, 110 cost 5 or more. When cross-referenced with the number of non-evolution creatures that cost 5 or more regardless of power, we find that this number represents about a third of the 323 creatures available.

This means that Searing Wave destroys roughly 80% of the creatures that can be summoned before it can be cast, under normal circumstances, and around 30% of the creatures that can usually only be summoned after the threshold point for casting it is usually reached. The important thing here is that it destroys them no matter how many of them there are.

This is considered sufficient justification for applying an errata, but further research was done in order to discern exactly which errata should be applied, with minimal change occurring to the card at the points where its casting is fair. As such, an attempt was made to even out all casting scenarios.

Against 1 creature of 3000 power or less, the shield penalty was removed, since the card is overcosted by two in this case.

Against 2 creatures of 3000 power or less, the shield penalty was removed and a penalty of a single mana card of the caster's choice, implemented. This was primarily for aesthetic reasons, considering that it will usually be a tapped mana card which is chosen. It allows for the user to be slowed rather than sacrificing a possible shield which they might not have needed anyway.

Against 3 creatures of 3000 power or less, the shield penalty was removed and a penalty of two mana cards of the caster's choice, inflicted. Part of the reasoning for this involves the fact that with Corile weakened, decks that hold off the opponent and do not attack, become even more susceptible to Searing Wave than before, and unlike the cost 6 Burst Shot, this card can be more easily used by other decks with small creatures since it does not affect their side. Attempts by such decks to use this card when the opposing field consists of 4 or more creatures, will result in a depletion of their mana zone that slows further effort, whilst still allowing the spell to be cast as a finisher.

In the end, the chosen errata attempted to weaken Searing Wave when used to tip the balance at any point where both players have built a large field of potential attackers, but have not attacked. The errata's effect extended well to the issue of the card being casted from low mana points and used to destroy large numbers of creatures, or used at high mana points in conjunction with other cards, since it costs 2 less than its closest counterpart Apocalypse Vise. It does not limit the function of the card on the turn it is used unless the opponent loses 6+ creatures, and for some reason the Searing Wave needed to be the first card used.

Fundamentally, Searing Wave has been made slightly stronger at all points where it was 'mathematically fair', and relatively weaker at all points where it was 'overpowered'. General functionality of the card itself remains unchanged, especially since the caster is given the choice of which mana cards are destroyed as penalty.

Result:

Name: Searing Wave
Type: Spell
Civilization: Fire
Cost: 5
Rules Text: Destroy all your opponent's creatures that have power 3000 or less, and call the number of destroyed creatures X. Choose X-1 of your mana cards and put them into your graveyard.
Mana Number: 1
Set: Rampage of the Super Warriors