Here's an explanation
Wicked Avatar's effect reads: During damage calculation, when this card battles a monster (Quick Effect): You can discard 1 Spellcaster monster to make your opponent take the battle damage you would have taken instead."**
When a Wicked Avatar battles any one of the God cards that is summoned using Tribute Summon, its effect activates by discarding a spellcaster to redirect attack damage to opponent
So the God card deals no effect damage to either players
Also when summoned correctly they are unaffected to card effect including targeting
Hence Wicked Avatar's effects won't activate at all, even when battling Obelisk The Tormentor , since his effect does not target