This skill sees very little use outside of PvP due to the overall already stellar sustain of necromancer, I suggest changing it so that instead of reducing the cost of the pets that it instead increase pet damage by 10 to 20% and giving major sorcery and savagery. Necromancer has been severely underperforming as of the last 3 patches being easily the worst class for 4 man content and being relegated to support in trials, this change could bring a bit more power and some very needed buffs to allow necromancer to compete as even in it's supposed good cleave capabilities it is currently being outparsed by both templars and most prominently DKs.
The class used to be the strongest for vKA where we have very static fights with some AOE being required, and now only its stamina counterpart is able to compete but even then it has a lower damage seiling than DKs, sorcs and templars while only being slightly above NB.
In here I don't mention warden as while the class is currently possibly the weakest in trials the balance problems go much further beyond it and much like the necro it's issues have been introduced in the last 3 patches, that being said, it's in a good position for 4man and PvP unlike the necro.