For Deathgrip, if I choose no unit to kill, can I still draw one or do I have to kill a unit to put it on the stack?

To answer your question, you must choose a friendly unit to kill when you play Deathgrip. You cannot choose "no unit" as a way to avoid the kill requirement.

According to RiftJudge FAQ #9295, Deathgrip targets a friendly unit. Because it targets a friendly unit, you must have a valid target available and select that target when you place the spell on the chain. If you have no friendly units, you cannot play the card at all.

Why you cannot "choose no unit"

1. Targeting Requirement: Rule 355.8 states that in order to put a spell on the chain, valid choices must be made for all targets. Since "Kill a friendly unit" is a targeted action, the friendly unit must be selected during the "Make relevant choices" step of playing the card.
2. "If you do" condition: The Might bonus in the text is contingent on the kill occurring ("If you do..."). If you fail to kill the unit (e.g., if the unit is saved by a replacement effect, as seen in RiftJudge FAQ #8668), you do not get the Might bonus.

What happens if you can't complete the kill?

If you play Deathgrip and the target becomes invalid (mistargeting) before the spell resolves, the kill instruction fails. However, as noted in RiftJudge FAQ #8668, you still draw the card. The draw is not contingent on the successful completion of the kill; it happens regardless of whether the unit actually dies or if the kill is prevented.

Summary of your options:

• Can you play it if you have no units? No, you must have a valid target to play the card.
• Can you choose "no unit"? No, you must target a specific unit.
• Do you draw if the kill fails? Yes, the card draw is not dependent on the unit successfully dying.

This is my interpretation based on the standard rules for targeting and the provided FAQs for Deathgrip. No official FAQ exists that explicitly says "you can play Deathgrip intending to have it fail," but the rules requiring a target to be chosen at the time of play make such a maneuver impossible.