I've been trying to make this body do something useful in a non-summoner build and couldn't.
Since life reduction is now useless against bosses, so is the liche king, and he lacks the damage to be of any help against both bosses or trash mobs. Arcane blast makes no difference, it is approx 1,5 times stronger than main attack which is still too low in legendary. Best I could make him do is 1,5K-2,5K (normal attack - arcane blast) with the help of deathchill, unearthly power and the circle of power. But then my character in same conditions does 7K per ternion projectile and 3-4-5 shots bosses before liche reacts to their presence.
(https://s8.postimg.cc/76o4vadt1/20180731133226_1.jpg)
His attacks do not convey pet damage from gear, thus he is only made stronger with % buffs like circle of power or nightmare's mastermind, which is still not much.
He can be used as decoy to distract bosses, but nightmare can do the same for 2 points.
This leaves him the role of the glorified debuff tool for 16 points which you can not control directly, slower than seal of fate.