Originally Posted by Fat CynicalGiant
Triple battles and rotation battles were new mechanics, and they were almost completely neglected by the competitive communities. I have a feeling the same thing will happen with this unless they don't make it optional.
They might also make happiness easier/faster to build up.
They may also make it drop down quickly, maybe even in battle.
An idea might be that natures or other personality details would affect how they gain happiness, like shadow pokemon in pokemon colluseum and xd. So if you have a pokemon with a certain nature or personality like "likes to fight", any time spend not using physical attacks would cause happiness to go down.
Perhaps if a pokemon takes too many hits at once or goes to long without putting a serious dent in a pokemon's health (this may or may not include status) they would lose a large amount of happiness, and even gain a status affect like scared or discouraged, which makes it stop following orders, or do less damage than normal, or take more damage, based on nature. This would probably make support pokemon more hit and run than stall, because could you stall when stalling might cause discouragement to go up and ruin your ability to fight?