diff --git a/src/boss.c b/src/boss.c
index bd694a11..aa830406 100644
--- a/src/boss.c
+++ b/src/boss.c
@@ -87,10 +87,6 @@ Color boss_healthbar_color(AttackType atype) {
 }
 
 static StageProgress* get_spellstage_progress(Attack *a, StageInfo **out_stginfo, bool write) {
-	if(out_stginfo) {
-		*out_stginfo = NULL;
-	}
-
 	if(!write || (global.replaymode == REPLAY_RECORD && global.stage->type == STAGE_STORY)) {
 		StageInfo *i = stage_get_by_spellcard(a->info, global.diff);
 		if(i) {
@@ -311,6 +307,9 @@ void boss_finish_current_attack(Boss *boss) {
 			if(p) {
 				++p->num_cleared;
 			}
+		} else {
+			// see boss_death for explanation
+			boss->extraspell = NULL;
 		}
 	}
 }
@@ -420,6 +419,27 @@ void boss_death(Boss **boss) {
 	if((*boss)->acount && (*boss)->attacks[(*boss)->acount-1].type != AT_Move)
 		petal_explosion(35, (*boss)->pos);
 
+	if((*boss)->extraspell && !global.continues) {
+		// unlock the relevant extra spell in spell practice mode if every spell of this boss has been cleared
+		// this is a temporary mechanic to make extra spells accessible until we integrate them into core game
+
+		StageInfo *i;
+		AttackInfo *spell = (*boss)->extraspell;
+
+		Attack dummy;
+		memset(&dummy, 0, sizeof(dummy));
+		dummy.info = spell;
+		dummy.name = spell->name;
+		dummy.type = AT_ExtraSpell;
+
+		StageProgress *p = get_spellstage_progress(&dummy, &i, true);
+
+		if(p && !p->unlocked) {
+			log_info("Extra Spell unlocked! %s: %s", i->title, i->subtitle);
+			p->unlocked = true;
+		}
+	}
+
 	free_boss(*boss);
 	*boss = NULL;
 	stage_clear_hazards(true);
@@ -495,6 +515,13 @@ Attack* boss_add_attack(Boss *boss, AttackType type, char *name, float timeout,
 	return a;
 }
 
+void boss_set_extra_spell(Boss *boss, AttackInfo *spell) {
+	assert(boss != NULL);
+	assert(spell != NULL);
+	assert(spell->type == AT_ExtraSpell);
+	boss->extraspell = spell;
+}
+
 void boss_generic_move(Boss *b, int time) {
 	if(b->current->info->pos_dest != BOSS_NOMOVE) {
 		GO_TO(b, b->current->info->pos_dest, 0.1)
diff --git a/src/boss.h b/src/boss.h
index bdca45c1..4c4fe6d3 100644
--- a/src/boss.h
+++ b/src/boss.h
@@ -94,6 +94,8 @@ typedef struct Boss {
 
 	int dmg;
 	Color zoomcolor;
+
+	AttackInfo *extraspell;
 } Boss;
 
 Boss* create_boss(char *name, char *ani, char *dialog, complex pos);
@@ -119,6 +121,8 @@ void boss_kill_projectiles(void);
 
 void boss_preload(void);
 
+void boss_set_extra_spell(Boss *boss, AttackInfo *spellstage);
+
 #define BOSS_DEFAULT_SPAWN_POS (VIEWPORT_W * 0.5 - I * VIEWPORT_H * 0.5)
 #define BOSS_DEFAULT_GO_POS (VIEWPORT_W * 0.5 + 200.0*I)
 #define BOSS_NOMOVE (-3142-39942.0*I)
diff --git a/src/stages/stage1_events.c b/src/stages/stage1_events.c
index 118fcc5b..77166799 100644
--- a/src/stages/stage1_events.c
+++ b/src/stages/stage1_events.c
@@ -382,6 +382,7 @@ Boss *create_cirno(void) {
 	boss_add_attack_from_info(cirno, stage1_spells+1, false);
 	boss_add_attack(cirno, AT_Normal, "Iceplosion 1", 20, 20000, cirno_iceplosion1, NULL);
 	boss_add_attack_from_info(cirno, stage1_spells+2, false);
+	boss_set_extra_spell(cirno, stage1_spells+3);
 
 	start_attack(cirno, cirno->attacks);
 	return cirno;
diff --git a/src/stages/stage2_events.c b/src/stages/stage2_events.c
index 3c0ed1e2..46231c87 100644
--- a/src/stages/stage2_events.c
+++ b/src/stages/stage2_events.c
@@ -652,6 +652,7 @@ Boss *create_hina(void) {
 	boss_add_attack(hina, AT_Normal, "Cards2", 17, 15000, hina_cards2, NULL);
 	boss_add_attack_from_info(hina, stage2_spells+1, false);
 	boss_add_attack_from_info(hina, stage2_spells+2 + (global.diff > D_Normal), false);
+	boss_set_extra_spell(hina, stage2_spells+4);
 
 	start_attack(hina, hina->attacks);
 	return hina;
diff --git a/src/stages/stage3_events.c b/src/stages/stage3_events.c
index 3d4fa02b..33fc9f16 100644
--- a/src/stages/stage3_events.c
+++ b/src/stages/stage3_events.c
@@ -958,6 +958,7 @@ Boss* stage3_create_boss(void) {
 	boss_add_attack_from_info(wriggle, stage3_spells+3, false);
 	boss_add_attack(wriggle, AT_Normal, "", 20, 20000, stage3_boss_prea3, NULL);
 	boss_add_attack_from_info(wriggle, stage3_spells+4, false);
+	boss_set_extra_spell(wriggle, stage3_spells+5);
 
 	start_attack(wriggle, wriggle->attacks);
 	return wriggle;
diff --git a/src/stages/stage4_events.c b/src/stages/stage4_events.c
index 3d895598..ecfde987 100644
--- a/src/stages/stage4_events.c
+++ b/src/stages/stage4_events.c
@@ -1092,6 +1092,8 @@ Boss *create_kurumi(void) {
 	if(global.diff > D_Normal) {
 		boss_add_attack_from_info(b, stage4_spells+6, false);
 	}
+
+	boss_set_extra_spell(b, stage4_spells+7);
 	start_attack(b, b->attacks);
 
 	return b;
diff --git a/src/stages/stage5_events.c b/src/stages/stage5_events.c
index 910ff99b..f73b06f1 100644
--- a/src/stages/stage5_events.c
+++ b/src/stages/stage5_events.c
@@ -795,6 +795,7 @@ Boss *create_iku(void) {
 	boss_add_attack(b, AT_Normal, "Bolts3", 20, 20000, iku_bolts3, NULL);
 	boss_add_attack_from_info(b, stage5_spells+2, false);
 	boss_add_attack_from_info(b, stage5_spells+(3 + (global.diff > D_Normal)), false);
+	boss_set_extra_spell(b, stage5_spells+5);
 
 	return b;
 }
diff --git a/src/stages/stage6_events.c b/src/stages/stage6_events.c
index 2daefff3..04c7511b 100644
--- a/src/stages/stage6_events.c
+++ b/src/stages/stage6_events.c
@@ -1328,6 +1328,7 @@ Boss *create_elly(void) {
 	boss_add_attack_from_info(b, stage6_spells+5, false);
 	boss_add_attack(b, AT_Move, "Explode", 6, 10, elly_baryon_explode, NULL);
 	boss_add_attack_from_info(b, stage6_spells+6, false);
+	boss_set_extra_spell(b, stage6_spells+7);
 	start_attack(b, b->attacks);
 
 	return b;