Water Weaver Feat

You have mastered a special connection to water and can beckon it to your call. You gain the following benefits:

Prerequisite: 4th level, Wildling

• Ability Score Increase. Increase your Strength, Dexterity, or Wisdom ability score by 1, to a maximum of 20.
• Water Walker. You can walk on top of surfaces made of water as if they are solid ground.
• You gain the Water Whip special attack (below).

Water Whip - Active Ability (Attack, Supernatural)

• When you take the Attack action on your turn, you can replace one of your attacks with creating and using a whip of water. You can slam this into a creature within 30 feet of you, forcing it to make a Strength saving throw. On a failed save, the target takes a number of d8 damage equal to your proficiency bonus, and is knocked 10 feet in a direction of your choice (including straight up, if you so choose). On a successful save, the target takes half as much damage and isn’t moved.
• Once you use this ability, you cannot use it again until you complete a short or long rest.

Source: KCLL, page 193

Mystic Path Feat Save DC:

• Any time a mystic path feat requires an ability score modifier for spell attacks or saving throws, use Constitution as the modifier. The DC is calculated as 8 + your Constitution modifier + your proficiency bonus.
• If your class grants you a spellcasting feature, you can use that ability modifier for calculating spell attack rolls and the DC instead of Constitution.