Personally, I like instant speed a lot.
But here's my analysis:
Runious Path feels a lot like Shriekmaw, only different
other cards care about each. Pod/Creature recycle cares about 'maw, where spell-based decks (think
Snap,
YPeezy) care more about Path.
Comparing the two bodies, Ruinous Path gives you an extra power but no evasion at the risk of opening your land to removal (which
isn't shouldn't be a concern if you're paying 7 for it). If I'm playing this slot for the creature (4/4 land for 5BB vs 3/2 Fear for 4B) specifically, I want Shriekmaw.
BUT, the other thing to consider is how many and which Planeswalkers you have in your environment? Do you value being able to remove them in black? Do you need to remove them? I see you (Eric specifically) only have 6:
Only
Ajani sticks out to me as being able to protect himself well against creatures (vigilance is super strong with PW).
Do you value being able to kill these walkers over being able to deal with huge haste threats like
Thundermaw,
Hellrider or
Conscripts?
So in summary, you've got three options (I know you only posted two and I shoved a third one in... deal with it):
and depending on
exactly what you want out of this piece of removal, should decide your choice.