Obi Wan Kenobi, Soresu Master

Defender, First Strike

Obi Wan ignores keywords or abilities that would prevent him from blocking an attacking creature.

Form III - Whenever Obi Wan blocks an attacking creature, until the end of your next turn,
he can attack as though he didn't have Defender. When Obi Wan attacks like this, he does not tap
and he becomes unblockable.