Weles is one of the most important gods in the slavic religion, who cares about the folcks and protect it against the wolves. He's the king of the underworld, Navia, where he welcomes the dead souls.

Level 3: Weles adept

You are an ally of Weles, so you are also for animals. The Beasts with a intelligence score of 5 or lower don't attack you, as long as you have not shown aggression towards these beasts. If the beasts are charmed or controled by someone else, they can do a Wisdom Saving Throw , the DM choose the DC (It can't exceed 25), proportionally to the charmer's power. You can also ad 1d4 to your Animal Handing Ability Checks.

Level 3: Weles Spells

The magic of your patron ensures you always have certain spells ready; when you reach a Warlock level specified in the Weles Spells table, you thereafter always have the listed spells prepared.

Weles Spells

Warlock Level	Spells
3	Shield, Animal Friendship, Detect Thoughts, Barkskin
5	Clairvoyance, Conjure Animals
7	Polymorph, Fabricate
9	Awaken, Raise Dead

Level 6: Weles's reaper

Weles is the god of the underworld, where souls go and reside forever, helping him extract the mineral riches of Navia. When a creature drops to 0 hit points in your line of sight and its soul is not protected or sucked away by something else, you can use your reaction to conjure a number of shadow equal to the creature's danger level (its level, if applicable) divided by two. You control the shadow, they can do normal tasks or fight for you. When the shadow is destroyed, the soul of the creature is free.

You can use this feature a number of times equal to your Charisma modifier (minimum of once), but you can use it no more than once per roll. You regain all expended uses when you finish a Long Rest.

Level 10: Weles Henchman

Now can you spawn Poltergeist instead of Shadow when you use Weles's Reaper ability.

 You also become more resistant, like Weles. You add 2 to your Constitution Score and you add your Constitution Modifier to your Armor Class. You add 2 Hit Points per level.

Level 14: Żmij

You can tap into Weles' strength to transform into Żmij into an action, the Weles's Dragon (use the Adult Black Dragon profile). You gain all the stats block of the Adult Black Dragon, within its hp, AC, skills and immunities. When you die when you're the Żmij, you return to your normal form and take the exess damage. You can also return to your normal form as a bonus action. If you're the Żmij and you're, killed by lightning damage, you die instantly and you return to your normal form. 

Once you use this feature, you can’t use it again until you finish a Long Rest unless you expend a Pact Magic spell slot (no action required) to restore your use of it.