the meaning actually becomes more clear if you encounter the same usage for に, it has many usages but this particular one means something like “in a … way”, for your example it means “in a big way” or in another word “very”
another example is 急に, 急 alone means sudden but with に it becomes “in a sudden way” or in another word “suddenly”
i just noticed you reached level 60, I’ll miss those people who always comments about you explaining things even though you’re “not in a high enough level” or something