Ninja to Gokudou

Both are gory shows dealing with a fight between factions who have been enemies since the ancient Japan. 

Both anime have two sides, one good and one evil, clashing against each other for their ideals, with members of both side falling one after the other as that clash scalates. 

Both shows deal with two clans fighting in some sort of all-goes-by battle royale to prevail over the other. Difference is that in Basilisk both clans are ninja, while in Ninja to Gokudou is instead a ninja vs yakuza conflict.