the reason per the manga and out of Feilong's mouth when asked by Asami as to why are u here. Feilong said bec. they(the enemy) are in my territory. and bec. of Takaba. He has no reason to get rid of Asami.
mafias has their own geopilitics like a propre country but it's underground world; Asami is hard to deal with him, he is always a step ahead of all others mafia (hong kong, russia, south korea...), if they can eliminate him they will gain lot of things , A perpetual fight ! for regular organisation "countries" it's a war for oil, petrodollar, Water conflict , gold and precious metal ... for criminal organisation it's drugs war, weapon's black market, humain trafic.... believe me or not mafias and governments have a mutuel agreement coz money makes the world go round.... Aaron want to kill Asami BUT Feilong knows Asami very well and respect him . by the way I love Poutine (≧∀≦)
right. These three guys are at peace now
the purpose of feiling's sudden visit is ......to help Asami , it's the real objective then comes others goals secure his territory, eliminate a pontentiel ennemy, and preserve the balance and peace with others mafia ! others than feiling will take this chance and get rid of asami but he knows this man more than others like Aaron , he belittle Asami and don't know his value!