Re: certain people
This reminds me of a player in a game on another site, and listening to his poor GM trying to avoid a TPK. The player had the GM approve, one by one, a combo of items, skills and spells, without the GM realizing how he planned to make them work together. Somehow (I forget even what I did know of that) it allowed the character to shrink and carry all the other characters, and either forced or convinced the others to go along, that his character was strong enough to carry them past trouble. So he's carrying them into the big situation, which the whole party had a decent chance with, but no way one character did, no matter how unbalanced a combo he'd managed to sneak past the GM, and the others couldn't use their resources from their hidden, shrunken state.
I saw that player in other games too, he was a great rules lawyer, had a great imagination for the way things could work in combos others, even experienced GMs, hadn't thought of, but too arrogant to the good of either himself or those swept up into his plans.