Can A Kinetic Blast delivered via the feat Delayed Blast trigger Sneak Attack damage?
Delay Blast
You can delay your kinetic blasts.
Prerequisite(s): Base attack bonus +3, kinetic blast class feature.
Benefit(s): When you use a kinetic blast, you can specify a number of rounds between 1 and 5. When that number of rounds has passed, the kinetic blast takes effect at the beginning of your turn. In the interim, you can take a standard action that provokes attacks of opportunity to cause the blast to take effect earlier than you initially selected. If you delay another blast while you already have a delayed blast pending, the previous delayed blast dissipates harmlessly.
Example with Aether Element Kinetic Blast-
Aether Kinetic Blast: You throw a nearby unattended object at a single foe as a ranged attack. The object must weigh no more than 5 pounds per kineticist level you possess. If the attack hits, the target and the thrown object each take the blast’s damage. Since the object is enfolded in strands of aether, even if you use this power on a magic weapon or other unusual object, the attack doesn't use any of the magic weapon’s bonuses or effects; it simply deals your blast damage. Alternatively, you can loosen the strands of aether in order to deal damage to both the object and the target as though you had thrown the object yourself (instead of dealing your normal blast damage).
You substitute your Constitution modifier for your Strength modifier if throwing the object would have added your Strength modifier on the damage roll, and you don’t take the –4 penalty on the attack roll for throwing an object that wasn't designed to be thrown. In this case, the object’s special effects apply (including effects from its materials), and if the object is a weapon, you must be proficient with it and able to wield it with one hand; otherwise, the item deals damage as a one-handed improvised weapon for a creature of your size.
Now player sets delay to 2 rounds and throws a shuriken or other item that could stick to the target and said target does not notice. Do they get sneak attack damage at the end of the 2nd round where the Kinetic Blast was set up for?
Best Answer
Yes... sort of.
You may add your sneak attack damage if your attack required making an attack roll. This includes attack rolls made with spells or thrown weapons. Clearly, sneak attack works with Aether Kinetic Blast.
Now let's factor in Delay Blast. Delay Blast does not alter the fact that you're making an attack roll; it only alters when that attack roll is made. As long as you're within sneak attack range (usually 30 ft), you can add sneak attack damage to the blast damage.
However, I don't think it quite works the way you're describing. Let's assume for the sake of argument that your GM agrees a shuriken can "stick" to the target (this isn't really defined in the rules, but ok). Delay Blast does not say you make the attack roll now and the blast happens later; it says "the kinetic blast takes effect" during a later turn. This includes the attack. So it doesn't turn your shuriken into a time-bomb; think of it as your kineticist charges the shuriken with kinetic energy, and a short while later the shuriken hurls itself and deals sneak attack damage.