I've had bad experiences with paradise fish together, and also with a paradise fish and tetras... not sure if mine was an evil one, but in general they don't seem to do well with small tetras. I separated my paradise fish because they attacked each other, and one in a 10g went after most platies but left danios alone, and one in a 37g ate the eye out of one black neon and a hunk of gill cover off another (that paradise fish got returned to the store). You would want a passive paradise fish to try it with.
Also, be aware that they are VERY, VERY GOOD JUMPERS. They can and will find the holes around your filter and use them for escape purposes...