Does Haste Stack
Again, youre going to need a good ability to offset that, and thankfully, this version of Ob Nixilis has that covered
Its been erratad to creature type Avatar Praetor, so if youre really, really desperate an 18th Praetor after exhausting the three each of the Phyrexians (along with Gix and Guildpacts Sanguine Praetor, also erratad), then there you go
Its death trigger isn't anything to write home about either, as it either puts three lands from your library into your hand or creates an X/X green spirit token where X is the number of lands you control
Because they have basic land types, your fetch lands can grab them too
You could easily cast an aura to lock down a troubling creature and then buff Light-Paws at the same time