When you score a critical hit with a melee weapon attack, you can roll one of the weapon’s damage dice one additional time and add it to the extra damage of the critical hit.

When you aren’t wearing armour, your base AC is 13 + your Constitution modifier.

When you are reduced to 0 hit points but not killed outright, you can drop to 1 hit point instead. You can’t use this feature again until you finish a long rest.

Being born without eyes has made life a struggle, but the strong must survive. You have blindsight out to 30 feet as long as you are not deafened or in an area of silence, in which case you gain the blinded condition. To see outside this range, you must make a DC 10 perception check. This check is a free action on your turn, but in active combat the DC is 15. 

Your Strength score increases by 2, and your Constitution score increases by 1.

You know common and celestial.