You have to use that lock on and attack with your swords on both of his "arms" to first destroy them and then attack the main boss and finally that little green core thing in him. (That move you learned just before that lets you also hook on to enemies in mid air instead of just those purple flower thingies.)
The settings.blk file in the game folder is a preset, you need the one in C:\Users\UsernameHere\AppData\Local\Blades of Time\ which is where the actual settings are stored.
Also they had a pretty messed up launch, first the keys got sent out and then withdrawn again as it appears a old build of the game had been sent to Steam instead of what it should have been, then this was fixed yesterday or at least it should have but it seems they timed it poorly so the keys were sent many hours before the fixed files were provided so in the meantime a hotfix had to be released to prevent a game stopping bug early on with a door that always closes.
After that the fixed game build was finally uploaded and around one gigabyte of content updated, trainer might still be compatible actually since it focused much more on the game assets although Steam usually always updates the main game exe but I don't think it was altered. (Instead that hotfix file got replaced yet again, unsure what function it has but it seems pretty important, kinda like a .dll file actually but it's not quite that either.)
I'll give the trainer a try when I'll next play the game, should work just fine. (As another miss the game is currently only provided via YuPlay and as a Steam registration key but Steam should probably also offer it soon enough.)
Can anyone confirm if changing the settings.blk file actually works for God mode? I'm thinking of getting this game, but I need to know about this first. I want to be able to have inf. health this way incase the trainer doesn't work for me (i.e. boss fights). Any info on this would be greatly appreciated.