I have Beastman Shaman in game and i play Blood Summoning and corrupt 4 unit.

I can draw 4 or 1 card?

sorry for the bad english

Thx.

4 cards.

Since Beast Shaman says " When a Chaos unit you control is corrupted... " it triggers on each individual unit being corrupted.

If it were worded " When one or more Chaos units you control become corrupted... " then you would only get 1 card because it would be triggering on each action that corrupts units as opposed to each unit being corrupted.

Make sense?

Yes, sorry for the wrong place