Min-Maxing (lvl1 25AC Fighter) - How to deal with OP Chars as a DM?

[ComaVision]

Throw a level one wizard with Grease (isn't that a first-level spell?) prepared at him. When he falls into a spiked pit. Then have a boulder crush him.

Then have the wizard urinate on him while yelling, "Is this making it past your AC?!"