The "TP Bonus" refers to this weapon doing WS dmg as if 100% more tp was used during the actual WS.
If you Savage Blade with 100% TP this weapon will add 100% TP to that yielding that much extra dmg (as if you had 200%) to WS's that are dependant on TP (not all WS's have proportinal dmg with TP)
FFXIclopedia mentions Savage Blade in this context, but it will add 100% to any sword WS.
However this weapon must be main-handed for it to take effect.
A very underrated sword for BLU. If you look at the TP mods for Savage Blade, you'll notice that it's fairly weak at 100% and 200%, but pretty strong at 300%. If you can get your TP to 150-200% by your next Chain Affinity recast, it'll give that much more of a kick to your SB+Cannonball or SB+Disseverment skillchain. Keep in mind this sword must be in the main hand.
Don't be ashamed to use this if you don't have Perdu or Hofud or Beast Slayer, it's a really nice option given the price.
I tested the "TP Bonus" out, and found this is a great weapon. I'm surprised it's taken me so long to learn of this sword, and I've not seen anyone else with it.
i augmented 2 of these in Valley Of Sorrows and got +2 Dark RES and +1STR and i got +1STR +1 Magic Attack so that makes just that little bit better for my BLU :D i would post a pic if i didn't play on Xbox and it is a ball ache to do it for them