Logia Type

Logia-Type Devil Fruits allow the user to wield, produce, and apply natural elements at will. They allow the user to partially transform into the element. Examples include the engulfing of the user's body into flames (Mera) or flying as a light ray (Pika). Unlike other devil fruits, Logia-Type Devil Fruits grant the user a Logia bar. This passive ability allows Logia users to dodge up to 20 non-Haki-infused incoming attacks from projectiles and enemies.

Best way to grind Logia bar dodges is to go to Sandora and agitate Lucid's Righthand and every Lad, then let them shoot you. If you're on low hp, block their bullets until you fully heal.

Fun fact about old logia users is that they could train up to 30 dodges. However, they are still maxed at 20 dodges in the current game. The only benefit to this is that it constantly tries to regenerate the dodges because it never maxes.