Vengevine‘s triggered ability is pretty easy to understand and deal with in most situations. But because the conditions placed on when it triggers, how it works in some games can get a bit odd.

The easiest way think of Vengevine’s trigger is that it will trigger if these two conditions are true; 1) Vengevine is in your graveyard when you complete the process of casting a spell and 2) this spell is the second creature spell that you have cast this turn. (Additionally, this Vengevine will only be returned to play if it remains in your graveyard from the time that the ability triggers until when the ability resolves.) That seems pretty simple, but there are some odd interactions that can come up.

The ‘game’ does keep track of what spells were played each turn. Vengevine’s ability will trigger if it enters the graveyard after the first creature spell of the turn is played. The Vengevine does not have to be in the graveyard when you cast any other spells, just your second creature spell of that turn. Similarly, this ability will NOT trigger when you cast a third or fourth creature spell in a turn, regardless of where the Vengevine is.

Also, if you have a Vengevine in play and sacrifice it to activate the ability of Ashnod’s Altar during the process of playing the second creature spell of that turn, the ability of the Vengevine you just sacrificed will trigger. This works because a spell isn’t cast until the announcement process is completed.