The second wave of orcs takes the form of wyvern riders. On wyverns! Their swooping and fly-by attacks will no doubt cause us problems, so I do something to try to make us less of a target. I cast a spell, and a dome of ice protects us, with an opening at ground level to keep us aware of the rest of the orcs.
'Don't worry lads', I say, with a wink of my eye, 'I've got this.' But the wyvern riders are somewhat prepared. Rather than having to land, they fly over the ice dome and drop firebombs on it to melt the ice. But, of course, it isn't ice, it's just an illusion, me being an illusionist, and making an obvious wink when I said it would protect us.
The firebomb drops through the illusory ice dome, surprising the GM as much as it does Thrak. Maybe taking the two feats Spell Focus (Illusion) and Greater Spell Focus (Illusion) weren't a waste after all.
Instead of melting the ice, the firebomb explodes a few feet from most of the party, deafening Salvador and Thrak. Aggar's curious about how it will effect Salvador's Duskblade spellcasting 'Does being deafened impose a spell-failure chance?'
'I think so. The status effect is detailed in the PHB.'
Thrak is curious about something too. 'What does deafen do to us?'
'...not hear the question I just answered?'