Level 2

• The spell's duration is 10 minutes.
• Your concentration on the spell cannot be broken by taking damage.

Level 5

• You gain one more use per long rest. If the spell would end, you can extend its duration by another 10 minutes by consuming another use.
• When your quarry dies, you can move the mark as part of making an attack against a creature you can see within range.

Level 9

• The damage increases to 1d10.
• The spell does not require concentration.
• You can apply the damage bonus on spell attacks as well as weapon attacks.
• If a creature under your control attacks a marked creature, it can also apply the bonus damage once per turn.

Level 13

• You regain one use every short rest.
• You are no longer required to see a creature to target it with this spell or to switch the mark to it, provided you know its location, and the range increases to 600 feet.
• You always know the location of a marked creature provided it is on the same plane as you, and you can see it through illusion magic like invisibility.

Level 17

• The damage increases to 2d6.
• Whenever you hit a creature within range on your turn, you may mark it as part of that attack, either expending a use to cast the spell, or extending an existing mark to also cover them. There is no limit to the number of marked creatures you can have, but they all end when the spell ends.

Favored Enemy

Choose one category: Beasts, Fey and Plants; Dragons and Monstrosities; Constructs, Elementals, Giants and Oozes; Aberrations, Fiends and Undead.

When you make a skill check relating to one of the chosen creature types, you are considered proficient in the skill, and if you were already proficient, your Proficiency Bonus is doubled. For example, tracking or grappling them, recalling information about them, or discerning their motives. Humanoids are excluded entirely; you are not an assassin.

You also learn one language associated with the creatures (respectively: Sylvan, Draconic, Silent [~Primordial], Infernal).

This improves when you reach certain levels in this class:

• Level 6: Select an additional category, and you can change one of these choices whenever you finish a long rest (you do not change languages).
• Level 14: If you make a saving throw in response to a favored enemy, you are considered proficient in the save, and if you were already proficient, your Proficiency Bonus is doubled.
• Level 20: If you make an attack roll against a favored enemy, you are considered proficient in the weapon, and if you were already proficient, your Proficiency Bonus is doubled.

Natural Explorer

Choose one common type of favored terrain: Forest, hill, plain, water. And one rare: Arctic, desert, swamp, underground.

You have advantage on ability checks and saving throws relating to the chosen terrain types. For example, climbing vines in the forest (Athletics check), persevering in the icy north (Constitution save), or spouting lore about undersea biology (Nature check).

You might benefit from a relevant terrain regardless of the surrounding area, like water terrain helping cross a river in a forest. Urban areas are outside your field of work entirely (including constructed areas even if they're in a forest or cave), and extreme or magical terrain is excluded but could be learned in specific circumstances (e.g. if you brave the elemental chaos' fire sea, you might add lava as a terrain).

At level 6, 10 and 14 in this class, you select one additional common and rare type.