Sephiroth represents vengeance and chaos in all forms, as his story arc follows his creation, rebellion, and finally attempts to ascend to godhood
Here, there be outlaws
Multicolor and Hybrid Everything said about Hired Poisoner is true of Pitiless Gorgon, with the exception of mana efficiency
There are a few permanents that offer more doubling up of counters, as well as ones that save counters from removed creatures, but even without these, Counter Blitz is very powerful right out of the box
as well as non-combat reuse of comes-into-play creatures (Jilt your own Flametongue Kavu, perhaps?) Barrin's Spite was a rare in this block and served generally the same purpose as Jilt, except that Jilt was an instant, and Jilt allowed you to unsummon your own creature if need be
And the maps are way less of a downside