Toad - Mortimer Toynbee

Greetings,
His text says
Two questions:
1) Does the damage happen before or after the attack step starts?
2) If it is after, does this damage get applied during the same time as say Black Widow: Tsarina's ability would activate, or during say the global step when damage can be applied?
Thanks,
PC
His text says
While Toad is active, when your opponent ends his main step, choose one opposing character who must attack this turn. * That character takes 2 damage."
Two questions:
1) Does the damage happen before or after the attack step starts?
2) If it is after, does this damage get applied during the same time as say Black Widow: Tsarina's ability would activate, or during say the global step when damage can be applied?
Thanks,
PC