Whenever a player casts a spell that targets a single player, each player rolls a six-sided die. Change the target of that spell to the player with the lowest result. Reroll to break ties, if necessary.

When Sengir Autocrat enters the battlefield, create three 0/1 black Serf creature tokens.
When Sengir Autocrat leaves the battlefield, exile all Serf tokens.

Serrated Arrows enters the battlefield with three arrowhead counters on it.
At the beginning of your upkeep, if there are no arrowhead counters on Serrated Arrows, sacrifice it.
, Remove an arrowhead counter from Serrated Arrows: Put a -1/-1 counter on target creature.

As Shimmer enters the battlefield, choose a land type.
Each land of the chosen type has phasing. (It phases in or out before its controller untaps during each of their untap steps. While it's phased out, it's treated as though it doesn't exist.)

Urza's Contact Lenses enters the battlefield tapped.
Urza's Contact Lenses doesn't untap during your untap step.
As long as Urza's Contact Lenses is untapped, all players play with their hands revealed.
Clap your hands twice: You may tap or untap Urza's Contact Lenses.

When Veteran Explorer dies, each player may search their library for up to two basic land cards and put them onto the battlefield. Then each player who searched their library this way shuffles it.