Above video demonstrates blood trails and splatters in Kanchayudha combat system. The techniques i have used here is, particle emitters and decals.
A particle emitter (blood particle) is attached to the sword of each character. when a character make a successful hit on another character, the blood particle emitter is activated and makes a trail of blood along the way of the sword swinging. (detecting hits is another topic for another article)
In order to make the effect realistic, there should be blood splatters on the surfaces where blood particles drop. To make that effect, in UE4, there is an event in particle emitters "OnParticleCollide". using this event, we can retrieve the location of particle collision. Now, we can spawn a decal (with a blood splatter texture) on that place to make the effect of spilled blood