I'm stuck on challenge 3 I have no room to special summon "angmarl the fiendish monarch" after I use "mega ton magical cannon" and have 6 spell counters left on "magical exemplar" to special summon him.
Use Magical Citadel first then use Blue Medicine and Spell Reclamation counter, discard Cerberus then use Exemplar skill to summon Cerberus. Use Blue Medicine and flip Mandragola, summon Angmarl by tribute Mandragola and use it's skill to draw medicine. Use medicine again then use cannon, remove spell counter from Exemplar and Magical Citadel first then from Cerberus.