Notes
Allow me to explain:
Staff of Myrddin is a great item that allows you to use an ability twice after ulting. Great for most Mages (if not all). However, with Perseohone, this ideal item isn't as great:
To put it simple,
Grasp of Death is almost all the time followed by
Bone Rush if the enemy is at a distance. In this scenario,
Bone Rush would be cast twice, so at least here,
Staff of Myrddin works wonders.
BUT what happens if you use
Grasp of Death at short range?
If you know what you are doing, then you should proceed with a few casts of
Harvest and then
Flourish for a devastating combo. Now picture that scenario for a bit: If you ult and then use
Harvest,
Staff of Myrddin will proc on you first use, but
Harvest is an ability that you can use up to 6 times without triggering it's cooldown, so you would be wasting an item's passive almost every time. Now you can understand why this item isn't really a good one, at least not on
Persephone.
Polynomicon is also not a good item. Persephone relies heavily on her basic attacks to activate
Harvest, so unless you time really well where you are goint to use your basic attacks without triggering your plants (and losing
Polynomicon's effect), then you shouldn't even think of buying this item.
i know what your problem with myrddin is but in my opinion even if you dont make any use out of the passive its still better than obshard because you get 120power and can get divine and still have max cdr.
the main reason why obshard is just a really bad item in my opinion espacially for persephone is you want to poke with a lot of hits on her multiple 2 and stuff you will only get the passive for very little of your damage in a fight it can also be wasted on minions and capms so in general i just dont think the passive does a lot espacially on a god that does its damage in multiple hits like multiple explosions.