[OP13-118_p1] - Monkey.D.Luffy (Carrying On His Will: Red Super Alternate Art)

If my Leader is mono-green, can I play a Character card with a base cost of 5 or more during the same turn I activated this [On Play] effect?

Yes, you can. However, in this case, you are also unable to set 4 of your DON!! cards as active.