You can't use Drink of my foes with double slice. Drink of my foes is a single weapon icon not somthing desigened to work with two weapons.Twin Stars.
But anyway, last action to me covers the activity and not its subordinate actions.
An activity typically involves using multiple actions to create an effect greater than you can produce with a single action, or combining multiple single actions to produce an effect that's different from merely the sum of those actions. In some cases, usually when spellcasting, an activity can consist of only 1 action, 1 reaction, or even 1 free action.
The text makes it clear that activity-contained subordinate actions are still actions in their own right.
It also chooses to keep "activity" separate and isolated from ever being an "action" by default.
This means that the text requires and provides specific and narrow instruction to consider the initialization of an activity as an action for the sake of preventing activity chains from being used when effects call for a raw-action.
Where I'm going with that is just to say that "activity" is a very narrow and specific term. There is no context in which you read "action" and are supposed to translate that into "action & activity."
If the text of Drink, etc, intended for activity action chains to be incompatible, it would have done that in the text, with something to the effect of
"Your previous action was a Strike, and it was not a subordinate action."
Because yes, subordinate actions are still their respective actions. They are only modified specifically as their activity instructs.
An activity can choose to *not* invoke or chain a "Strike action" if it wants to avoid being compatible with effects that trigger from Strike specifically.
When the devs think "hey, it would be a bad idea for this damage action to be compatible with Strike effects" they do that, and there is no Strike action.
The most obvious player-known example is Elemental Blast.
The new swarm eidolon does the same, and imo is a better example here.
When dispersed, your eidolon scatters its component bodies across a wider area, increasing its size by one category (to Large for most swarm eidolons). It has a reach of 0 feet, can’t make Strikes, and can occupy the same space as other creatures. While dispersed, it can use the Swarming Assault activity.
If you mis-apply the subordinate action text to mean that activities are wholly separate in concept, and not a chain of their subordinate actions, guess what?
That would mean that this text only blocks raw-Strike. All subordinate Strikes would be valid to a swarm eidolon and only that "base Strike action" would be blocked. Tandem Strike, even SMN's version of reactive strike, and all other subordinate strikes would be valid.We already know that's not how the game works; the subordinate actions inside activities really are their "raw actions" done in sequence for all considerations except for the single override put into the text. The initialization of an activity is *not* the same as starting it's first subordinate action, effectively injecting a "ghost action" at the start of every activity before the component actions.
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Letting subordinate actions trigger things like Sneak Attack, etc, is the same rule-thread that results in "previous action was ___" still checking that last action, subordinate or not.
If you try to reinterpret the text so that activities "box" all their actions away, that affects a whole lot more than "previous action" considerations; no outside ability remains able to trigger from nor modify subordinate actions.