I am looking for a romance manga. The specifics I want from it is these:
Must include one or all of these if it can be found:

Male lead (a must have)  
Traumatic past  
Strong or op  
Might be bullied but later on he trains or does something to fend of those bullies  
Fantasy environment  
Comedy  
Obviously the partner or his crush has to be a girl  
Can either be a manga or a mahnwa  
Could start of weak but have amazing potential and trains to get there  
Of he is not op or strong it would be nice if he has cold demeanor and can hold a mysterious past which makes the heroine more interested in him  
Arranged marriage but the guy has no idea about it

Must not have and it can't have any of these characteristics:

Yuri or yahoi  
Bad plot  
Where the main lead does not die at the end and also his lover too unless the main lead sacrifices himself for a greater good  
The lead is purely useless

You could try Doulou Dalu, it's not purely a romance manga, though romance is one of the important aspects.

Dou Po Cang Qiong is a possibility. The magical guy lost all his powers for mysterious reasons, and starts off weak and powerless. But his girl sticks by his side, and is always sure he'll make a comeback. He grows stronger by leaps and bounds in the story.

Hekikai no AiON
Full Metal Panic! and Full Metal Panic! Σ

Thank you guys.. !!! 🙂 Really appreciate it. 😉 If there's more recommendation... let them come. 😛