When you cast a level 1+ Martyr spell, you can take 10 Radiant damage to use one of the following benefits. This damage ignores your Resistance and Immunity, and bypasses your Temporary Hit Points.
Heighten
Once on each of your turns, when you cast a spell that forces a creature to make a saving throw, you can give one target of the spell Disadvantage on saves against the spell.
Quicken
When you cast a spell that has a casting time of an action, you can change the casting time to a Bonus Action for this casting. You can't modify a spell in this way if you've already cast a level 1+ spell on the current turn, nor can you cast a level 1+ spell on this turn after modifying a spell in this way.