Explain to me how blocking works again?

So here's the situation.

My opponent attacks with all his stuff, I block with 3 of my miinions. He plays [Hearthstone Card (Judgement) Not Found] on his [Hearthstone Card (Ancient Yeti) Not Found] which wipes my board. However, despite having a blocker on the yeti (which died) he still punched my face.

I thought blockers would remain as "phantom blocks" if killed by a spell before combat?

Or does Overwhelm beat through phantom blockers? (because I never encountered that before)

If the blocker of an Overwhelm minion si removed before combat resolves, than the attacker inflicts full damage because the "placeholder" for the blocking minion is considered as having 0 health.

Quote From Nirast

Yes, Overwhelm would still punch you in the face.

well....at least now I know...I could have won that game.

goddammit

Overwhelm also punches through barrier--i.e., if he didn't have JudgementBADCARDNAME and you had blocked the Ancient Yeti with something and then gave it barrier, then your blocker would take no damage but your nexus would receive 5.  (Not sure if that's as intended or not, but that's how it currently works.)

Quote From OldManSanns

Overwhelm also punches through barrier--i.e., if he didn't have Judgement and you had blocked the Ancient Yeti with something and then gave it barrier, then your blocker would take no damage but your nexus would receive 5.  (Not sure if that's as intended or not, but that's how it currently works.)

I'm pretty sure the blocking unit's health is still subtracted from the Overwhelm damage in the case of Barrier.

It's just that the damage assigned to the blocker is then negated (not the overflow damage to the nexus).

If a minion with Barrier block one with Overwhelm, the blocking's health is subtracted from the attacker's damage that still pass onto the Nexus. Barrier prevents the defending minion's death by negating the damage it should suffer.

Also if a spell with Drain targets a minion with Barrier, the protection is removed but there isn't any healing. In order to get an actual heal the spell must inflict damage.