Base Class: Barbarian
The spirits of are touched by your love and grief for those you lost and have bestowed on you magical powers to protect those you are still brave enough to care about despite fear of losing them.
Strike of vengance
Starting at 3rd level, While you are raging, if an ally creature or player is at 3/4 health or less, your attack rolls have advantage against the creature that hit it last and your rage damage is increased by 1d6 when attacking that creature. If multiple allies are at 3/4 health or less, this only applies to the lowest health one's attacker.
Sacrificial healing
At 6th level, you may use a bonus action to take 1d6 necrotic damage and heal up to 15 damage between 1 or 2 allies and gain the ability to do so again after a long or short rest. You can not use this when raging.
Vengeful heart
Starting at 10th level, choose one type of creature (undead, elementals, fey, ect) or one type of humanoid that isn't celestials, or the race you are, that killed your family. You have advantage on attack rolls and saving throws against them and deal an additional 1d6 damage against them. Your unarmed strikes are magical for the purposes of resistance and immunity to nonmagical damage.
Pain of grief
Starting at 14th level, if an ally is killed in combat, you use a bonus action to cast power word kill on the killer, if the killer is the kind of creature that killed your family chosen at level 10, you deal 2d12 radiant damage first. Then roll a d20, if it is 10 or higher you successfully cast true resurrection on the killed ally if power word kill failed, or revivify if power word kill succeeded. You then suffer 2 levels of exhaustion and can't use this ability again until your exhaustion level is zero and you finish a long rest.
Defensive anger
At 3rd level, while raging, after a creature attacks an ally, your next attack roll against them has a +1 bonus