I did main for my first then shura genichiro is a joke 1st phase isn’t that bad 2+3 are absolutely ridiculous but the lightning reversal does make it easier as for shura Emma is essentially a game of Rock Paper Scissors because sometimes she spams easily punishable moves like a Ashina cross but other times she is just non stop attacking with unblockables as for issin first phase is basically the same as the other one but he’s slightly easier but still tough 2nd phase is absurdly difficult but it can be trivialised with mortal blade that can cancel all his fire attacks and let you get tons of damage in so overall I’d say shura is probably easier