How is an effect that would result in multiple types of changes handled in terms of layer application?

The correct answer is that each effect applies in its appropriate layers and/or sublayers. This principle aligns with the way the Magic: The Gathering rules are structured regarding layers of game effects.

In the game, the layer system is designed to apply various types of effects, such as those that modify characteristics of a permanent, in an organized and specific order. Each layer serves a distinct purpose for applying effects pertaining to power, toughness, abilities, or other characteristics, allowing for diverse interactions and combinations of those effects.

When multiple effects are in play, they evaluate and apply according to the defined layers. This means if there are effects that modify toughness and others that modify power, they will be processed in their respective layers instead of clumped into the same layer or disregarding any effects.

In cases with conflicting effects in the same layer, the last one applied is the one that ultimately takes precedence, but this does not mean that all effects are forced into one bucket; rather, each effect appropriately utilizes its designated layer. Thus, understanding the proper application of effects within their layers is vital for accurately judging the outcome of interactions in gameplay situations.