how much cheese can you get away with?
You can really rack up the damage as an evoker using metamagic + metamagic reducers...
1. Arcane thesis: choose 1 spell you know, all metamagic of that spell now cost 1 level less.
This is abuseable because the wordings do not prohibit using +0 level metamagic giving you -1 level per metamagic added... however, your DM will likely not allow that. Still, split ray, twin spell, empower, and maximize are very nice.
2. Easy metamagic: choose one metamagic feat, it now takes 1 less level higher, to a min of 1 level higher. (so a +1 metamagic is still +1, but a +2 is now +1, a +3 is now +2)
3. Metamagic school focus: Choose a spell school, you can apply metamagic feats to spells in this school 1 level lower X times per day. Also a limit of +1 min
4. rods of metamagic: you can apple a metamagic feat to a spell on the fly, for free, X times a day.
5. various classes get special metamagic abuse... I think incantantrix and initiate of the 7 fold veil. IIRC.
Combine all of those metamagic reducers together. And suddenly you are doing enough damage to one shot anything without good dex + evasion...
The painful thing about banning conjuration is that you lose out on teleport, dimension door, etc...