A gate to Mechanus opens in the nearest unoccupied space to the shield and 5 inevitables enter the plane. They attempt to stop the combat and negotiate a settlement, and leave peaceably if they are not attacked. The gate stays open until they leave.

fruit trees of every variety appear all around the shield, filling 1d4 acres. They grow to maturity in 1 turn. If the shield is struck 30 feet or more in the air, a cloud island a la a cloud giants castle appears for the trees to root into.

1d12 random creatures within 60 feet of the shield gain the ability to cast phantasmal force at will.

All weapons in a 15 foot radius from the shield are repelled away from the wielder to the edge of the radius, including their own. this effect lasts 1d8 rounds and moves with the shield.

a square purple cloud 50 feet to a side appears over the striker and rains a random potion for 1d4 rounds. All struck by the rain are effected by 1 dose of the potion per round of exposure.

The wielder and the striker instantly swap all worn possessions, including the shield.

The striker gains 15 ranks in a randomly chosen profession.

a 20 foot radius sphere within 150 feet of the wielder fills with copper pieces, which then react normally to local environmental conditions. The wielder gets to chose where the sphere goes, but doesn't know what will happen otherwise.

The shield transforms into a non-magical sponge of the same shape for 3 rounds. Any damage done to the sponge remains when it changes back.

15 pixies, 15 grig, and 15 satyrs spill out of the shield. They try to start a party for 2d6 rounds, bringing all of their abilities to bear, then scatter if unsuccessful.