Deathtouch
When Jessie Zane enters and whenever you cast a Snake spell, conjure a card named Ambush Viper into the top six cards of your library at random. It perpetually gains "When this creature enters, draw a card."

Flying
Rankle has lifelink and haste as long as an opponent controls no creatures.
When Rankle enters, you may pay 1 life. When you do, each player discards a card and sacrifices a creature.
Whenever a player discards a card, Rankle perpetually gets +1/+0.

Whenever another creature enters under your control, that creature perpetually gains haste if its power is 4 or greater. If its toughness is 4 or greater, you gain 4 life. If its mana value is 4 or greater, seek a creature card.

Starting intensity 0
When Teysa enters, create a 1/1 white and black Spirit creature token with flying. Teysa intensifies by 1.
Spirits you control get +X/+0, where X is Teysa's intensity.
At the beginning of your end step, you may exile Teysa. If you do, at the beginning of your next upkeep, return Teysa to the battlefield under its owner's control and it gains haste.

Lifelink
When Saint Elenda enters, conjure a card of your choice from Saint Elenda's spellbook into your hand. You may cast that card this turn without paying its mana cost.
At the beginning of your end step, if you gained life this turn, create an X/X white Avatar creature token, where X is the amount of life you gained this turn.