Hi Hi! Firstable, I really like your name LOL (if its a One Piece reference that is...).Looking at usage stats and sample teams it seems like bulky Dragonite is the most used mon. Why do you think that is the case when in OU Dragonite is must more based on offense alone.
Dnite is interesting, looking at usage stats the most common tera options are Flying and Normal (from what I remember) which are used in offensive builds, so Dnite it is used offensively for the most part but the matter of fact is that Dnite is the most versatile mon in the format atm, can do pretty much everything and everything does it well, from phazer to trapper to sweeper to breaker to disrupter... Can be physical or special attacker, even mixed. If you have an idea of a build im pretty sure Dnite can do it and all thanks to its entire kit, well rounded stats with a solid typing, a high Face-to-Face performance with Multiscale + strong priority moves, very good Tera user but can also do really well without it and has access to incredible utility moves like Encore, Thunder Wave, Fire Spin, Roost and Dragon Tail.
Multiscale plus Tera is HUGE, the more time passes the more offensive the metagame has become and this favors Dnite since its one of the best (if not the best) in the Face-to-Face archetype (the somewhat equivalent to Hyper Offense in BSS) where is pretty difficult to win a 1v1 against it.
Regarding Booster Energy, oh yeah, it is common (not as common as it was back then tho) Bundle and All Mighty Flutter Mane are the best users, Roaring Moon made a little comeback last season and Pokemon like Iron Moth and Great Tusk where really strong users a couple of season back (Moth can be seen but people started to run HDB). Quickly looking at the top25 ranked teams from last season there where 9 booster energy users which is pretty high number in my opinion.In a similar vein I’m surprised booster energy mons aren’t on every team. It feels like booster energy would be even better in a shorter format where the mon in question is on the field with its boost longer.