No.1 Sentai Gozyuger Episode 48- "Resolve to Reform the World! In Winds Of Calamity!"
 

Mashiro and Hoeru are the final round... until FireCandle arrives!

So, Fire Candle went full-on Lu Bu after absorbing Rex's essence. *Looks at calendar* It is the year of the Fire Horse after all, so might as well, I guess.
AAAAANNNNDDD Mashiro went Ultra Instinct.

All jokes aside, what a real tearjerker, this episode.

I didn't expect Rex to have instant killing ability. Because Rex has this ability, I feel he almost represents the concept of death despite death being officially represented by previous Sentai minions in the Calamity group.

Fire Candle in his new form looks very cool. Maybe his new form can be categorized as an Evil Sentai Ranger?

More of an antagonist with a kickass suit, probably. I'd say he's in the same category as Wolzard (the purple version, not Fire) or Bio Hunter Silva.