[conf]Knight of the Mists AI cancel extra U-not destroy crit

Describe the Bug:
1- Knight of the Mists: AI only can play it not pay extra
and not be obliged to target a Knight creature.(This happens only when both players have a Knight creature if AI only has a Knight at least Knight of the Mists itself always pays the cost).
2- Not a bug but AI needs some hint as even if opponent has a knight creature which AI can target AI prefers at times to pay the extra
cost even when it can select not to pay and destroy opponent's knight.
Which card did behave improperly?
Knight of the Mists
Which update are you using? (date, name)Which type? (duel, gauntlet, sealed deck)
Manalink 2016/08/27: Eldritch Moon v2, duel
What exactly should be the correct behavior/interaction?
1- Knight of the Mists: If AI doesn't pay the extra
cost has to target a knight creature no matter if opponent has or hasn't got a knight creature.
2- AI when opponent has a knight creature has a hint to prefer not to pay the extra
cost to destroy opponent's knight creature.
Are any other cards possibly affected by this bug?
-

2- Not a bug but AI needs some hint as even if opponent has a knight creature which AI can target AI prefers at times to pay the extra

Which card did behave improperly?
Knight of the Mists
Which update are you using? (date, name)Which type? (duel, gauntlet, sealed deck)
Manalink 2016/08/27: Eldritch Moon v2, duel
What exactly should be the correct behavior/interaction?
1- Knight of the Mists: If AI doesn't pay the extra

2- AI when opponent has a knight creature has a hint to prefer not to pay the extra

Are any other cards possibly affected by this bug?
-