Can a player use Assault of the Kraken to initiate an additional challenge during the Epic Phase?
Event text:
Response: After you win an unopposed challenge,you may initiate an additional challenge of the same type this phase (this additional challenge must be the next challenge you initiate). If that additional challenge is opposed, neither player wins the challenge.
To be a little more specific on the debate, let's say the Epic Phase is created by Battle for the Shield Islands(because it's text stating "may declare a single challenge" might specifically prevent this):
Plot: After the dominance phase this round there is an epic phase during which each player may initiate a single challenge of his choice. Characters with 1 or more
enhancements may be declared as attacker or defenders while kneeling. Instead of normal claim, the winner of each challenge may choose and take control of a location controlled by the losing opponent. (Place this card next to your plot deck until the end of this epic phase.)
If this cannot be done, what if the Epic Battle did not state "single challenge" and instead stated "a challenge"?