Responses
1.nekrateholic
2.lollipop dragon
3.kusari ni kiss
since nekrateholic characters arent introduced umtil kusari ni kiss its kinda hard to tell which comes first but if you read nekrateholic first you will get a deeper explaination on vampire/half-vampire/dragon type relationships and if my memory serves me correctly a better explaination on helsings past with atsumi
1. Lollipop Dragoon
2. Kusari Ni Kiss - http://www.mangago.me/read-manga/kusari_ni_kiss/