can i exile a creature with Soulherder that returns to the battlefield at the beginnig of the endstep, for example when it was exiled with Venser, the Sojourner before ?
(like do i need to have a target when the trigger goes on the stack?)
(like do i need to have a target when the trigger goes on the stack?)
Yes. You always need to have a target for that ability as it goes onto the stack.
603.3. Once an ability has triggered, its controller puts it on the stack as an object that’s not a card the next time a player would receive priority. See rule 117, “Timing and Priority.” The ability becomes the topmost object on the stack. It has the text of the ability that created it, and no other characteristics. It remains on the stack until it’s countered, it resolves, a rule causes it to be removed from the stack, or an effect moves it elsewhere.
603.3d The remainder of the process for putting a triggered ability on the stack is identical to the process for casting a spell listed in rules 601.2c–d. If a choice is required when the triggered ability goes on the stack but no legal choices can be made for it, or if a rule or a continuous effect otherwise makes the ability illegal, the ability is simply removed from the stack.
601.2c would be the selection of "another target creature you control" for Soulherder's ability. The target creature needs to be a creature (i.e., on the battlefield) at the time you choose it; you can't just hand wave "there will be another creature once that other ability resolves Real Soon Now".
Private Mod Note
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Rollback Post to RevisionRollBack
Why bother with mere rulings when so many answers can be found in the Rules?
(like do i need to have a target when the trigger goes on the stack?)
601.2c would be the selection of "another target creature you control" for Soulherder's ability. The target creature needs to be a creature (i.e., on the battlefield) at the time you choose it; you can't just hand wave "there will be another creature once that other ability resolves Real Soon Now".
RULES OF MAGIC :
http://magic.wizards.com/en/game-info/gameplay/rules-and-formats/rules