If a unit has both 'I must be assigned combat damage first' (like Caitlyn) and 'Tank ... last' (like Doran's Shield), what happens in combat with another friendly unit?

Ruling: Your opponent gets to choose which of the rules they will follow. They either need to assign damage to it first or assign damage to it last.

Nuances:

• When a unit has only these effects and no other friendly units, it is both first and last, so there are no problems.