The Clix Gentelman Explains 001: Venom Dr. Strange vs. Venom Groot
As you always should, let's begin by quoting the powers.
SUMMON HELP FROM THE VENOMVERSE When Venom Dr. Strange hits an opposing character, if no character has been placed this turn, after resolutions you may roll a d6.
[3-6]: Choose a character from your sideline whose name includes "Venom" of equal or less points to place adjacent. This game that character can't be carried, replace or be replaced, and returns to your Sideline at the beginning of your next turn.
REGROWN FROM A TWIG AND FROM A DROP When Venom Groot is KO'd, instead of putting him in your KO area, turn him to click #1 and put him on this card. This game, when another friendly character uses "Call In Help From the Venomverse" and succeeds, they may instead choose to place Venom Groot from this card (He's scored each time).
For the purposes of our discussion, VG was placed on your sideline for the purpose of VDS' trait. On your turn, VDS hit an opposing character and successfully rolled for his trait, placing VG adjacent from your sideline.
On your opponent's turn, they were able to KO VG, triggering his trait. He was then placed on his card, rather than the KO area, and your opponent's turn ends. At the beginning of your turn, VG returns to your Sideline.
The Comprehensive Rule Book Supplement, or CRS, has this to say on pg. 9.
Unless an effect specifies otherwise, characters off the map can’t: activate actions, have effects they can use be triggered, apply their passive effects, trigger effects, or be targeted/chosen by effects. Characters off the map are still part of your force and will count for rules and effects that look for characters on your force. The following additional rules apply to a character being removed from the map:
If, before the character was removed from the map, it activated or triggered an effect with a duration or that set up a delayed resolution or trigger; the effect with the duration will continue and expire normally, and the delayed resolution/trigger will still resolve/trigger and can still affect the character off the map.
So, VDS' trait chooses VG while he is on the Sideline, so being off the map doesn't stop VDS' trait from working. The rules specifically allow for a delayed trigger, which “at the beginning of your next turn” is. Even if you find a way to KO VG on your own turn and then use Call In Help From the Venomverse to place him from off of his card, he was still brought into the game via VDS' trait and placed on your sideline for the purpose of that trait. So, the delayed trigger will always apply to him. And since VG can't be replaced, there is no way to “lose” that effect.
Even if VG returns to your sideline and a friendly character with the Call In Help From the Venomverse trait hits and makes their roll, they will not be able to choose VG because he is no longer on his card.
So sorry friends, there is no way to “cheat” VG onto your main force with Dr. Strange.
Hopefully this article cleared up the interactions for you and can serve as an easy reference in the future.
If you have any questions or comments, you can send them along to firstname.lastname@example.org
Until next time, please be courteous, be kind, and read the rules.