It's also possible to build a Zinnia Commander deck to maximize enter effects, and here's a few cards to help begin that process: Panharmonicon - this four-mana artifact has a static ability that says if a creature or artifact entering would trigger an ability of a permanent controlled by the player, that triggers twice instead
The best blue creatures often have low casting costs, allowing you to save mana for the rest of your spells and get them onto the battlefield early
So we can use Sliver Overlord to fetch Shields of Velis Vel, turning all our opponents' creatures into slivers, and then gain control of all of them with the Overlord
Because there was so little blocking going on, and because the creatures were so aggressively costed (you won't see too many two power evasion creatures for two mana anymore much less having multiples in the common slots of each color), games tended to end on turn five
Olivia is a 3/3 Vampire Assassin with flying and lifelink for four mana
It provides a steady stream of ETB triggers with its uptick, while both downtick abilities let it win the game through different means for a versatile value engine