User blog comment:HfEvra/PvZ2 plants in PvZ2C (Modern Day)/@comment-5760976-20160917235737/@comment-26813439-20160918000644

Maybe it could work like this:

Level 2: Faster recharge.

Level 3: Flames get a larger area of effect.

Level 4: Might be boosted when planted.

Costumed: Green wisps stay for longer.