aDovahkean
Sonic the Hedgehog, a franchise with plenty of debated Eras and even more Continuities, some far more dangerous then others for an isekai victim as human as the egg-headed main antagonist himself with no super-intelligence or cheats or systems to speak of. Just meta-knowledge, lots of it, and by extension, plenty he can do with it.
Sonic Films? Fine. Sonic X, Boom, and Prime? Manageable. Gameverse? Dicey, but doable. Archie and Fleetway Comics? No thanks. Sonic SatAM and Underground? Better than dealing with any EXEs, still wouldn't even if his second life depended on it. Shame that he has no choice in the matter.
At least he can decide what to do after the fact, make the most of this situation he's stuck in. So what to do then? Join GUN? As if. Go the Chris Thorndyke route? Pass. Babysit the cinnamon roll-haired hologram that got carried along for the ride? Meta supposes that, exploiting plot holes aplenty, and causing chaos for all things canon will have to do.