Chara

Determination. After each reset Chara gains an extra dodge. 

Superior Evasion. Chara has advantage on all saving throws.

Dodge(1-???/day). When an attack or effect would do damage to Chara they can choose to instead take no damage.

Reset. When Chara would drop to 0 hit points time resets to one round before they encountered the group that killed them. If the ones who killed Chara succeed a DC 18 wisdom saving throw they have a vague recollection of the encounter. They make this check with disadvantage unless they are proficient in wisdom saves, and after the third reset they all make the save with advantage. 

Knife. Melee Weapon Attack. +11 to hit. On hit: 7 (1d4 + 5) piercing damage. 

Uncanny Dodge. Chara can use her reaction to half the damage they would take from an attack. 

Chara has 3 legendary actions. 

Movement. Chara can move up to 15 ft without provoking attacks of opportunity.