Two handed weapon, in one hand?

[Bigby FrostFire]

I'm sure this was answered before. I know that there is an archetype called the titan mauler which lets you use a two handed weapon of your proper size at a -2 in one hand and that was a feature which let you do that...But then I found this

Thunder and Fang (Combat)

You have mastered the ancient Thunder and Fang fighting style, allowing you to fight with increased effectiveness when wielding an earth breaker and klar.

Prerequisite: Str 15, Two-Weapon Fighting, Weapon Focus (earth breaker), Weapon Focus (klar)

Benefit:You can use an earth breaker as though it were a one-handed weapon. When using an earth breaker in one hand and a klar in your off hand, you retain the shield bonus your klar grants to your Armor Class even when you use it to attack. Treat your klar as a light weapon for the purposes of determining your two-weapon fighting penalty.

Normal: An earth breaker is a two-handed weapon, preventing the use of a klar in one hand without imposing penalties for using the earth breaker one-handed. A klar can be used either as a one-handed weapon or a shield; it does not grant a bonus to AC during rounds in which it is used as a weapon.

Now it clearly states taking penalties for using an earth breaker one handed. Which has me all jumbled up. The only thing I can think of us using an earth breaker one size smaller than you making it one handed not two. Is there something I missed in the rules some where that had made the titan Mauler's Class feature worthless?

[DM_Blake]

No, there is no general rule that lets you use any 2H weapon with just one hand. You cannot simply take penalties for it because it cannot be done at all. So the part of the feat you bolded that says "without imposing penalties" has no bearing on general rules but the rest of it does: this feat lets you use the earth breaker with one hand.

Now, there may be feats or traits or class abilities or spells or whatever that exist today, or might exist in the future, that provide a specific exception to this general rule. If any such specific exception lets someone use a 2H weapon with only one hand, with penalties, then Thunder and Fang would let them ignore those penalties with an earth breaker.

As for using a small earth breaker, anybody could do that and would not need this feat to do so. It would cause a -2 to hit, so probably that means that using this feat would let you use your itty bitty earth breaker without that -2 penalty, but it would also let you upgrade to a normal sized earth breaker without a penalty, so you'd have to be really attached to the itty bitty one to not upgrade.

[James Risner]

@Bigby, you will run into heavy table variance on using an Earth Breaker in one hand without the other hand using a Klar. Some view that feat (Thunder and Fang) as allowing it without a Klar. Others (like me) view that is a required combat style.

In either case, if you use it one-handed. You are using a one-handed weapon, with one-handed power attack, and one-handed TWF penalties, and in no way two-handed.