Lucina can enter her shell as an Action. While in her shell, her AC increases by 4, she has Advantage on Strength and Constitution saving throws, and she is Prone. Her Speed becomes 0, she cannot use Reactions, and the only Action she can take is to emerge.

When Lucina hits a creature with a weapon attack, she can expend a use of Hunter's Mark to deal an extra 1d6 force damage to the target.

Lucina can expend a spell slot to regain 1d8 Hit Points per level of the spell slot as a Bonus Action. She can also remove one level of Exhaustion whenever she finishes a Short Rest.

Lucina can cast Misty Step without expending a spell slot a number of times equal to her Wisdom modifier per Long Rest. She also gains the ability to turn Invisible until the end of her next turn as part of the same Bonus Action.

Once per turn, when Lucina hits a creature marked by Hunter's Mark with a weapon attack, the attack deals an extra 1d8 damage.

Lucina has proficiency with martial weapons and can use a druidic focus or a component pouch for her ranger spells.

Lucina can mark a creature with Hunter's Mark. She always has the spell prepared, can cast it without expending a spell slot a number of times equal to her Wisdom modifier per Long Rest, and can cast it with a spell slot normally. She can maintain concentration on Hunter's Mark for up to 24 hours.

Lucina gains a Fighting Style feat. She has chosen Archery, gaining a +2 bonus to attack rolls with ranged weapons.

Lucina gains Expertise in two proficient skills. She has chosen Perception and Survival, doubling her proficiency bonus for those skills.

Lucina gains mastery with three weapons. She has chosen Longsword, Longbow, and Shortsword, gaining their weapon mastery properties when wielding them.

Lucina chooses the Hunter subclass. She gains Hunter's Lore and Hunter's Prey. Hunter's Lore lets her know whether a creature marked by Hunter's Mark has any immunities, resistances, or vulnerabilities. Hunter's Prey lets her deal an extra 1d8 damage once per turn when she hits a marked creature with a weapon attack. She has chosen Colossus Slayer.

Lucina's Speed increases by 10 feet while she is not wearing Heavy armor. She also gains a Climb Speed and Swim Speed equal to her Speed.

Lucina gains Defensive Tactics from the Hunter subclass. She has chosen Escape the Horde, making opportunity attacks against her have Disadvantage.

Lucina gains Superior Hunter's Defense from the Hunter subclass. Once per turn when she takes damage, she can use her Reaction to halve the damage, and she can use this feature a number of times equal to her Wisdom modifier per Long Rest.

Lucina gains Precise Hunter from the Hunter subclass. Her weapon attacks against a creature marked by Hunter's Mark ignore Disadvantage caused by the creature being unseen or hidden, and she knows the marked creature's location while it is within 60 feet of her.

Lucina can invoke the support of former military contacts and recognize the signs of organized military activity. In appropriate circumstances, soldiers and veterans may provide her with shelter, information, or limited assistance.