QI attack an enemy Underworld Watchman Khawy with this follower and both are destroyed. If I resummon this follower and evolve it with its Last Words ability, can my opponent destroy it with the Last Words ability of their Underworld Watchman Khawy?

AYes. Both this follower and the enemy Underworld Watchman Khawy are destroyed at the same time, triggering both Last Words abilities. Since you are the active player, you must resolve your pending abilities before your opponent can resolve theirs. Therefore, the evolved version of this follower will be on the field when your opponent resolves the Last Words ability of their Underworld Watchman Khawy.

QI put this follower into my EX area from an opponent's cemetery with the On Evolve ability of Octrice, Omen of Usurpation. If I summon this follower, then it is destroyed, how should I resolve this follower's Last Words ability?

AIf you pay the cost of this follower's Last Words ability, it will be put onto its owner's field before being banished.

1. When this follower is destroyed, it goes into its owner's cemetery.
2. When it is put into the cemetery, its Last Words triggers, and you can choose whether or not to pay its cost.
3. If you choose to pay the cost, you would banish a Naterran Great Tree from your field or EX area.
4. You would then put this follower onto your opponent's field engaged.
5. You would then evolve it. However, it can only be evolved by revealing its evolved form from its master's evolve deck. It is on your opponent's field, so your opponent is its master, and their evolve deck is a private zone, so you can't evolve it.
6. Since this follower wasn't evolved, it would be banished.

QIf I evolve this follower with its Last Words ability, can I evolve another follower using its evolve ability in the same turn?

AYes. Although you can only activate one evolve ability per turn, other abilities that evolve followers do not count towards this limit.

QCan I add this follower to my hand with Maid Leader's On Evolve ability?

ANo. Although this follower has an ability that evolves it, it doesn't have an evolve ability.