Reborn X Arcobaleno! Reader X Colonnello

(Y/N) was raised to be a hitman at a young age. She is the second best hitman in the world, right under Reborn. She travelled far and wide with her partner, Spade, a wolf. She received a summoning slip to go to the tallest mountain in the world. Finally, she arrived at the peak to find that there was no one there. Suddenly a blinding light shone, (Y/N) almost falling off the mountain if it wasn't for her partner who stopped her fall. Then the light dimmed. It took a bit for (Y/N) to gain her eyesight back, but when she did, everything seemed larger, even her partner, Spade. She found a nearby puddle only to find herself as a baby. (Y/N) didn't really mind her Arcobaleno form actually, but she was curious about it. She began her travels again and was told that there were 7 other babies around the world, similar to her. They were considered the 7 strongest babies, but now, there were eight.