Some final considerations.

[Lemon]

explain how "invading" a character's "mind with telepathy" is not powergamy in 300 words or less

the same reason a mind flayer in dungeons and dragons isnt powergaming when it blasts you with psychic abilities? its an innate ability of the creature, and in discovery, and RP in general, nomads have no power with their telepathy if the receiving player does not allow it to have any power. its up to you/other players to decide if theyre weak willed enough to get spooked by scary mental images.

powergaming generally defines your character having abilities/aptitudes they otherwise should not have, generally when in games being RPed without a diceroll system (discovery, space station 13, etc) and being exceptional at them. my station engineer character would be great at repairing the stations generators, half decent at fixing up a cyborg with mechanical damage, but dogshit at anything beyond basic first aid. they shouldnt be able to perform surgeries. but if they do anyway, thats powergaming.

what youre trying to say is its either godmodding (my character always succeeds no matter what!) or some level of metagaming and godmodding both (my character has read your mind and knows everything you know!)

i hope you learned something today

What Sombs said - you appear confused about what Powergaming is defined as in Disco and elsewhere.