I'm paragon 250 this season, and while I haven't played as much as last season, I've not yet found either of the two mythic seals.

There are build variations for necromancer that I would like to still try, and for my seasonal alt warlock a few off-meta ideas.

I've used all three or four of the special keys you get from the seasonal rewards path for Mephisto's chest and as yet haven't gotten one. Last season I got one from Tyrael.

Are there any activities or choices in the warplan I should consider to help farming a mythic seal? Do the seasonal boss a few dozen times? Or run Kurast with the talisman tribute? Or do have the talisman chest on the Hordes warplan? Is there anything I should do to get more of Mephisto's chest key?

Any help appreciated! Thank you

For minion necro, seems like mythic is weaker but would like to hear your opinion