Espeon is what happens when you take the "sunny" idea of time-of-day association of Espeon and by extension, Umbreon, and carry it out to a logical extreme. Although perky and full of sunshine, make no mistake, Espeon is a total ditz. An airhead. A cloudcuckoolander of the highest order. Because of this, she shows up often as a gag character and makes the most appearances out of Kirby's Eon friends. She can be unbelievably stupid, and every time you think she's reached her maximum stupid potential, she surprises you by out-dumbing herself each time. Espeon has a hard time retaining information and staying focused, and in other cases isn't even interested in learning, opting to draw her own nonsensical conclusions instead. She can also be a real chucklehead, laughing all the time at everything, or long after the appropriate time for laughing has passed. She can easily be convinced into doing just about anything, especially if it looks fun, as long as the story you spin is whimsical enough to appeal to her childish mindset, and for this reason, she easily gets into trouble. Sunlight and Espeon species connection aside, Espeon has always been an airhead, even as an Eevee. Evolution doesn't change a personality, though it may boost any feelings of self importance.
It is unknown if Espeon is either bad at remembering names or prefers to use cute nicknames for people instead, but she tends to refer to everyone other than Umbreon as something descriptive about that person, or whatever that person reminds her of. She repeatedly refers to Kirby as "Marshmellow Man", even as far back as the first time they formerly introduced themselves. Though many write Espeon off as a joke, her power itself is no joke. One psychokinetic pulse is enough to topple a large reinforced building and bust up a forest within 500 feet. She also has the power of telepathy and mind reading, but doesn't really know how to use it other than by accident, which causes her to freak out, thinking she's just hearing voices in her head instead. Espeon calms down at night and during overcast days, goes to bed early, and wakes up early too. She is often the first person to wake up in the house, and being bored alone with herself, will get up in the face of others to wake them up at the first crack of light beyond the horizon, before the sun even has a chance to make a proper appearance. Espeon becomes lethargic on very cloudy or stormy days. On the other hand, she tends to apply more effort to using her head as a trade off and is noticeably more lucid.
Espeon is also currently dating Umbreon, but it's hard to say how true of a relationship it is, as Umbreon doesn't really respect Espeon that much and is just too indifferent to do anything about it one way or another. Espeon, on the other hand, is all too giddy about having someone to cuddle with and talk to, on and on about nothing, all day long. One thing Umbreon will admit, though, is that Espeon is definitely cute. In fact, a lot of other characters know that Espeon is quite fetching, but are typically turned off by her behavior otherwise.