Normally, you have to use a light weapon to benefit from the Weapon Finesse feat. You can also use a rapier or a spiked chain with Weapon Finesse. You cannot use the Power Attack feat with a light weapon. Can you use a spiked chain or a rapier and benefit from both Weapon Finesse and Power Attack at the same time?
Yes. A rapier or a spiked chain made for a creature of your size is not a light weapon, even when you’re using the weapon with the Weapon Finesse feat. If you have both feats and use a
rapier or a spiked chain, you can manage power and finesse in the same attack.