The Training (weapon enchantment) ability says:
Popular among those who seek to impersonate skilled warriors, a training weapon grants one combat feat to the wielder as long as the weapon is drawn and in hand. The feat is chosen when this special ability is placed on the weapon. That feat cannot be used as a prerequisite for any other feats and functions for the wielder only if she meets its prerequisites. Once chosen, the feat stored in the weapon cannot be changed.
And Warrior Spirit (su), the Fighter's Advanced Weapon Training option, says:
The fighter can forge a spiritual bond with a weapon that belongs to the associated weapon group, allowing him to unlock the weapon’s potential. Each day, he designates one such weapon and gains a number of points of spiritual energy equal to 1 + his weapon training bonus. While wielding this weapon, he can spend 1 point of spiritual energy to grant the weapon an enhancement bonus equal to his weapon training bonus. Enhancement bonuses gained by this advanced weapon training option stack with those of the weapon, to a maximum of +5. The fighter can also imbue the weapon with any one weapon special ability with an equivalent enhancement bonus less than or equal to his maximum bonus by reducing the granted enhancement bonus by the amount of the equivalent enhancement bonus. The item must have an enhancement bonus of at least +1 (from the item itself or from warrior spirit) to gain a weapon special ability. In either case, these bonuses last for 1 minute.
This seems to me like this is an effective way of getting a combat feat of your choice, reminiscent of a Brawler's Martial Flexibility. For the low, low cost of having an already potent Advanced Weapon Training option.
However, it could be that Training's "lock in" means that taking the ability will always be the same feat.
Do I get to choose a feat for Training every time I activate Warrior Spirit, or would I always get the same feat?
Best Answer
You get to choose the feat each time you imbue the weapon
When you select the Advanced Weapon training option, this is what happens:
Here the option is Warrior Spirit (Su). The option text describes what it does when you use it:
There is no text in the option text or in the introduction about the options instructing you to select a special ability when you pick the option (and with which you then would be stuck), there is only text instructing you to select an ability when you use the option. So the ability allows you to imbue the weapon with any one weapon special ability every time you use it, not with only one specific pre-set weapon special ability.
However, keep in mind that the effect of imbuing the weapon is transient, so this is not as strong as you might think:
You spend one point of spiritual energy of the pool you have (equal to your 1 + your weapon training bonus: 2 at 5th level, 3 at 9th, 4 at 13th and 5 at 17th) to convert an already existing enhancement bonus into a special ability of the same value. Training is a special ability worth +1 enhancement bonus, so you will need a weapon that already has a +1 enhancement bonus naturally, or you need to first imbue it with such a bonus for a point of spiritual energy. Then you convert that +1 bonus into the Training special ability. At the end of the minute, the special ability (and its equivalent enhancement bonus) will end.
There is no mechanism that lets the weapon remember what special ability you chose the last time, when you use this again or care about this. For example, if you had a normal sword and this was a weapon from your main training group bonded for Warrior Spirit, and you were a 14th level fighter, you could spend 2 points to create a +1 enhancement bonus on it and convert it to a combat feat. You then can use that feat for one minute (if you meet its prequisites). When you do this again in the next fight on hour later, you can choose another feat. You even could do this process twice at the same time, as it carries no action cost, and gain two different combat feats from it at the same time, both lasting for a minute.
If you already have a magic weapon with a +1 enhancement bonus, you could use this for up to five fights in the day (depending on your level) by forgoing that enhancement bonus. But just using the option itself, it is quite costly limited in number of uses.