Does white cranes blow up ability happen before or after the control check for an attack? For a block that white crane blows up does that happen before or after the control check?

After the control check is made, and all costs are paid.

To both questions, it is after your opponent makes the control check. Remember cards are not considered played until a control check has been made and passed. Also it doesn't blow up anything, it is discarded and effects are negated.

So for the block they would have to fully/partially block successfully before white crane can choose to remove the block.

On a sheer technicality, no. The block would be cancelled and discarded before you even get as far as the game 'seeing' weather it is a full or patial block, it's just a legal block card sucessfully layed, actually generating the block if the effect of playing that card, and you dont' get as far as resolving the effect, just like cancelling any other card as it is played.

Totally semantic difference, but I like accuracy

Inquisitor M said:

Sorry Mr. M, I have to disagree with you, however in the end you are correct.

8.3.2.10 If a block is discarded from the card pool before the Damage Step. Then the
attack will still be considered blocked since the block quality was established and
the attack took on the completely or partially blocked status during the Block
Step.

As soon as an attack is blocked, the block effect is created.

However White Crane specifically states in the last line of her text "Discard it from their card pool, and cancel it's effects."

8.3.2.12.1 If a card effect would negate an action card’s effects, and the action cards was played as a block, the block effect is canceled.

The next version of the AGR will contain a line something to the effect of:

8.3.2.12.2 If a card effect would negate an attack card’s effects, and the attack cards was played as a block, the block effect is canceled.

Stamps for Aslum & H.