| Fuzzy-Wuzzy |
Ascetic Style says to choose, so you have to pick a specific weapon when you take it. But it doesn't say "this feat may be taken more than once," so you can only take it once, with a single weapon.
If you want to use it with multiple weapons you'll have to invoke the Special line, which gets you all monk weapons, but you have to be a 5th-level monk or have fighter weapon training with the monk group to do that. Dunno what your character is or has.
| Kazaan |
One other option is the Human racial feat Martial Versatility (prereq. Human, Fighter 4) lets you pick one feat that requires you to pick a weapon it works on and you can apply that feat to any weapon in the same weapon group. If you pick a weapon in multiple groups (ie. Seven-Branch Sword is in both Monk and Heavy Blades), then you could apply the benefit of Ascetic Style across both the Monk weapon group as well as the Heavy Blades group (eg. Bastard Sword).