Can I use the Graft ability even if the creature giving the counter only has one?

Question

So say I have Simic Initiate under my control and I cast Cytoplast Manipulator. The former’s Graft ability triggers and I choose to move its only counter onto the entering creature. Is that how that works? I’ve always thought that Simic Initiate would just die from it but my friend told me that, as it leaves the battlefield before the ability resolves, its no longer a legal graft.

Answer 1

Simic Initiate's ability would be rather close to useless if that were the rule. The counter moves as the ability resolves, not after.

We do have 704.122.5. which says

If an effect says to “move” a counter, it means to remove that counter from the object it's currently on and put it onto a second object.

This could be interpreted as saying that there's a moment in which the counters have been removed from Simic Initiate, but haven't been added to Cytoplast Manipulator yet. However, we have

608.2f Some spells and abilities include actions taken on multiple players and/or objects. In most cases, each such action is processed simultaneously.

So while 704.122.5.says that moving counters consists of two different actions. 608.2f says those actions are taken simultaneously.

We also have the question of why Simic Initiate would die. We have that one state based action is:

704.5f If a creature has toughness 0 or less, it’s put into its owner’s graveyard. Regeneration can’t replace this event.

And when are state based actions checked?

704.3. Whenever a player would get priority (see rule 117, “Timing and Priority”), the game checks for any of the listed conditions for state-based actions, then performs all applicable state-based actions simultaneously as a single event.

And when do players receive priority?

117.3b The active player receives priority after a spell or ability (other than a mana ability) resolves.

There's nothing that gives anyone priority while an effect is resolving, only after it resolves. Between the Simic Initiate losing its counter and Cytoplast Manipulator receiving it, no one receives priority, and no state based actions are checked.

On top of this, we have

112.7a Once activated or triggered, an ability exists on the stack independently of its source. Destruction or removal of the source after that time wont affect the ability.

So even if Simic Initiate were to die from its counter being removed, the effect of giving a counter to Cytoplast Manipulator would still take place.

Answer 2

Your friend is incorrect. Dying to having 0 toughness is a state based action, and state based actions are checked when a player would receive priority before they do. This means that the graft ability would fully resolve before the initiate would die (this is true of all creatures dying to damage or 0 toughness, unlike dying to spells that specifically say destroy, the creature is still there until after the spell or ability fully resolves)

The relevant rules on state based actions for this are:

704.3 Whenever a player would get priority (see rule 117, “Timing and Priority”), the game checks for any of the listed conditions for state-based actions, then performs all applicable state-based actions simultaneously as a single event. If any state-based actions are performed as a result of a check, the check is repeated; otherwise all triggered abilities that are waiting to be put on the stack are put on the stack, then the check is repeated. Once no more state-based actions have been performed as the result of a check and no triggered abilities are waiting to be put on the stack, the appropriate player gets priority. This process also occurs during the cleanup step (see rule 514), except that if no state-based actions are performed as the result of the step’s first check and no triggered abilities are waiting to be put on the stack, then no player gets priority and the step ends.

704.5 The state-based actions are as follows:

704.5f If a creature has toughness 0 or less, it’s put into its owner’s graveyard. Regeneration can’t replace this event.