For the longest time, I thought it was pronounced a-LOY-zee-us.
Aloysius is very swishy. It reminds me of
Sebastian Flyte's teddy bear in "Brideshead Revisited".
masculine list:
https://www.behindthename.com/pnl/191050/124079feminine list:
https://www.behindthename.com/pnl/191050/124080