If unit has at least 3 more HP than enemy at the start of combat, unit receives def+6 during combat.
Earth Boost 3
- Inheritable by all units.
Unlocks at 4 ★
There are four types of Boost skills, each powering up a unique stat (Fire increases attack, Wind increases speed, Earth increases defense and Water increases resistance). They come with only one condition: the unit must have more current HP than their opponent in order to trigger the stat boost. They are similar to Blow skills, requiring a condition to be met in order to trigger a sizeable stat increase.
Naturally, the most important factor when using these skills is managing the activation requirement. Certain types of units do not typically have much HP. Mages and ranged attackers tend to lack HP, while physical infantry and armor have higher values. This makes them a good choice to inherit a Boost skill. Inheriting a boost skill is a good way to augment a unit with a HP boon. Teams that have sources of healing are great candidates for a Boost skill, as they can keep their HP topped up and maintain the boost. Renewal is a nice skill to pair as is Falchion thanks to their latent healing. Many red units hover around 35 speed, and Wind Boost, arguably the most potent of the lot, will let them swing many matchups in their favor, while leaving B slot free for a different breaker skill.
Boost skills are difficult to circumvent, as the boost starts active regardless of who initiates combat. Attacking with a unit with more HP will nullify the skill, but may not always be a good idea, especially if they have weapon triangle advantage. The best strategy is to try and either chip down their HP or simply attack normally with a unit with advantage. Take caution, as Wind Boost grants a significant speed bonus, enough to significantly change that unit’s matchup spread.