I am writing a story. I'll post some of it here. I need anybody's opinions please!

CHAPTER ONE
Ciella ran around. She ducked into a small alley way. Her eyes widened. They kept chasing her. She jumped up and onto a wall and fell down. She kept running. She saw a blinding light and passed out. She woke up freezing cold and wet. It was raining like crazy. "Not now grell! You promised Sebastian! You did know ciel meant two days a week you get to see him right? that means you leave me alone FOREVER Grell!" she said and got up. Her outfit was ruined. "Great." She followed Grell in the rain to ciel's mansion. "Alois... seriously ..? first you want to kill him and now you wont leave HIM alone!" she sighed. Sebastian showed her to the guest room. "Aha.. uhm Sebastian.. it's grell time again. But grell if you're going to use your death scythe, take it away from ciel's manor.." Ciella fell asleep in the warm room. When she woke up it was night time. Sebastian walked back to the manor with grell. "Well. Grell had a fun day.." Grell was fangirling. "SEBASCHAN!" he fainted. "I'm off to put the young master to-" he found ciel stabbing a sword into Alois again. Claude immediately arrived. "Not so fast Claude~" Sebastian said kicking Claude away.
He smiled. "Now to take care of Alois and Ciel!" Sebastian ran over and took the sword away. He bandaged up Alois. Alois slapped him. "A sword to the side is what you get for trying to hurt my young master Trancy~" he said and escorted the crying boy outside in the cold rain. Claude followed him.
"That was-" ciel slapped him twice. "Young master I was dealing with Grell.." he picked up ciel and walked to his room. He unlocked it and set him on the bed. Ciel fell asleep. He snored quietly. He always fell asleep almost instantly with that pillow.. Ciella sighed. "I worry for ciel.. I know he is a demon but! That trancy fellow should've been dead by now" she facepalmed.
(the end of chapter one ^)

so i see you're doing a black butler fanfic
may i ask why there are so many small sentences? you can turn them into complex or compound sentences.

every time a different character speaks, you NEED to line break. it's a garbled mess and i cant tell who's speaking
also ciel is a proper name, capitalise it
and yes, the simple, short sentences are very jarring to read. :s

Whenever I capitalize it, it turns to ceil ;-;
thankyou. I'll do that! I will not fix it here though.. ^.^ it really helps me