规则 INITIATING ABILITIES有启动异能的步骤：

1. Check play restrictions: can the card be played, or the ability initiated, at this time?

 If the card or ability specifies one or more targets, check that it has at least one valid target. If the card or ability does not have at least one valid target, it cannot be played or initiated.

 2. Determine the cost (or costs) to play the card or initiate the ability and the player’s ability to pay them, taking modifiers into account.

 If both conditions are met, follow these steps in order:

 3. If playing a card, the player places that card faceup on the table in front of them. (This card is not in play.)

 4. Apply any modifiers to the cost(s).

 5. Pay the cost(s). If this step is reached and the cost(s) cannot be paid, abort this process without paying any costs.

 6. The card commences being played, or the effects of the ability attempt to initiate.

 7. The card is played or the ability (if not canceled in the previous step) resolves. The card enters play or, if it is an event card, its effects resolve and it is then placed in its owner’s discard pile.

If any of the above steps would make the triggering condition of an interrupt ability true, that ability may be initiated just before that triggering condition becomes true.

If any of the above steps would make the triggering condition of a response ability true, that ability may be initiated immediately after that triggering condition becomes true.

If the ability being initiated is on a card that is in play, the sequence does not stop from completing if that card leaves play during this sequence unless the card leaving play prevents a required cost from being paid.

在第1步检查是否有至少一个有效目标（valid target），这个时候如果有多个有效目标，不需要选中目标。在第5步支付所有费用。在第7步结算效果，这个时候才会选中要对其生效的有效目标。

对应到Hugin & Munin，在它进场后，尝试触发它的响应。在第1步确认是否有至少1个能重整的角色。如果没有，不能触发响应。如果有，在第5步支付费用。如果没有爪牙放置进场与你交战，费用支付失败，不结算效果。如果有爪牙放置进场与你交战，在第7步结算效果，选择要重整的角色并重整他们。