
JwT |

The Fluff:
Chitin's Doom was an ordinary buckler, found on the floor of the training room of a Thieves Guild by Lear Cain, a budding psionic warrior. Soon after he wore the shield, he was attacked by Rhagodashes, fearsome silverfish-like creatures from the Almedio Jungle. Lear had always been unnerved by such vermin, and this soon turned to outright terror as the creatures captured him in their nigh inescapable grasp, then began to fight over him like starving dogs over fallen table scrap. But the buckler, picked up by mere happenstance, repeatedly saved his life in that battle. Time and again the beasts jaws crunched inches away from Lear's face. And as Lear's fear began to shift to confidence in the newfound buckler, something began to change the buckler itself. Lear could sense that somehow his destiny was now tied to that once castaway hunk of wood.
Chitin's Doom is made out of a carved piece of drift wood.
Themes for the shield:
Nautical (Lear is a former pirate, and the entire campaign is nautical themed.)
Psionic (It must be psionic in nature; Lear is a psycic warrior.)
Vermin (The player HATES creepy crawly things, and this always bleeds into every character I have seen him play - so any sort of defense against bugs would be great.)
The Character is now 3rd level, so the first abilities should manifest soon.
I will post more once I get my mitts on my books, but I wanted to see what ideas y'all might have.
TIA.

Taliesin Hoyle |

Some ideas that may trigger some of your own.
The shield is driftwood, perhaps it is the humility and inobviousness of the shield that is its greatest strength. How about having the shield cast sanctuary three times a day. On the same theme, I would bundle that the shieild allows invisibility 1 x day invisibility to animals 1 x day and invisibility to undead 1 x day.
You mentioned that the shield made him hard to hit. How about it being a +2 shield against one opponent that the player designates, and a +1 shield against other foes.
Creatures of less than animal intelligence find themselves calmed as if by a calm animals spell.
The shield allows a reroll once every day, as per the Luck domain power.
The shield appears to be a brittle, fragile chunk of driftwood, but the wood is actually set in a force effect. That helps it to stop incorporeal and ethereal attacks. It can cast prot arrows three times a day and protects the user against magic missiles as per the shield spell.
I do not use psionics and have never bothered to read the rules for them, but here goes. a psionic scare effect. The shield adds + thingummy to any check that involves disintegrating or destroying matter in whatchamacallit x
The shield detects hostile intent and allows the user to influence the enemy telepathically to forestall combat, like a psionic sanctuary.

Chris P |

Ok so here's a couple of ideas. It would start as a +1 wooden bukler with the omen to humm when vermin are within 60ft. It should progress to at least a +3 shield over the coarse of say 15 levels (I assume it's not going to be a 20 level legacy weapon). It should give anti-vermin shell (or whatever the spell is called) 1/day and freedom of movement 1/day or for a number of rounds per day. It should give lesser restoration (for vermin poisons) and maybe even nuetralize poison. That's probably all that you can fit in a 15 level legacy item (I don't have the book in front of me). I would use the warrior or theif disadvantages progess, which will mean a lose of hit points and skill points. For rituals maybe the minor one should be to successfully escape a grapple from a vermin and the second ritual would be to single handedly kill a vermin of up to 2 HD less than the character. I know you want a psychic bend to it, so instead of the above mentioned spells use the psionic equivalent. I hope this helps.

Turin the Mad |

I had no idea that by legacy you meant a mechanic. I assumed you meant that the player had inherited the shield or that the shield had a litany of tales attached to it.
Legacy items do have a litany of tales attached to it. In this case, the player character with his humble driftwood Black Flag buckler is doing it 'as he goes'. (Consult Weapons of Legacy for more details.)