Stronger Then Ever (Gaara X Oc)

What would have happen if Hinata Hyuga had a identical twin named Hikari Hyuga, who called shisui uchiha "big brother" and had known uchiha clan since young

.....
"Are you lost little girl?" I heard a someone's voice

"W-who a-ar-are yo-you?" I asked looked at a big boy with onyx hair and onyx eyes he had konoha headband as well

"Don't worry little girl" he said patting my head "I am Shisui Uchiha" he said giving with closed eye smile
.....

after uchiha massacre tobi/obito decided to be friend Hikari (as he found her remind him of his deceased lover) and help her be strong, seeing that the little hyuga chakra has light purple colour similar to lavender instead of blue
.....

I don't own any of the characters other than my own oc and some other oc's