Heartflame Duelist

If an instant or sorcery spell you control with lifelink deals damage to you, you gain and lose that much life simultaneously. In this case, your life total doesn't change. (Your life total may increase if the spell also deals damage to other permanents and/or players, however.)

If an effect instructs you to choose a card name, you may choose the alternative Adventure name. Consider only the alternative characteristics to determine whether that is an appropriate name to choose.

Some instant and sorcery spells instruct other things to deal damage rather than deal damage themselves. In these cases, you won't gain life for that damage (unless the other things also have lifelink). Notably, a spell that instructs a creature you control to fight won't cause you to gain life.