No, cheese. Using invisibility to get passed someone/something is one of the uses it was meant for. Teleport Field can randomly teleport you around, so if it teleported you to the lich, then that's perfectly okay. You didn't load up a contingency was 3 ADHW or set a load of traps in a spot for the lich to step on. Instead, you took him down with good old fashioned fighting: that's perfectly non-cheesey
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