Some opponents can recover from that better than others, but its a better sweeper than focusing on islands or snow
Sephiroth, Fabled SOLDIER / Sephiroth, One-Winged Angel Death triggers and life loss go hand in hand, and they rarely look better than on Sephiroth, Fabled SOLDIER
This is cheaper than Teferi's Protection, and since it phases, that's better, but not by much
Patriarch's Bidding was an absolute fixture when it was legal in both Standard and Block Constructed, usually returning a whole swath of Goblins to the battlefield but also finding more amusing fringe uses as well
In those cases Ugin's kill index is much closer to how fast he can win by doing three to the face, sometimes gaining 7 if against burn
If a turn has multiple combat phases, the ability can only be activated before the beginning of the declare attackers step of the first combat phase in that turn