From my experience, a solo lvl 100 gengar can beat e4. You just at lest need 10 revives. I suggest replace hex with icy wind to help beat lance. Also try not to have same type moves in a set to maximize its verstility. The gengar I used have moves shadowball, dark pulse, psychic and icy wind. The last three moves mostly counter the three e4. Bruno(psychic), agatha(dark pulse) and lance(icy wind). For lance, you need at leaast 2 hits for most of his poke so here comes your revive buffers.