How is the Shin Megami Tensei series? I got a little interested after seeing the Fire Emblem crossover but wasn't sure if it was worth pouring time into.
Pretty fun! It's like pokemon if it was hard as shit. If you've played Persona 5 you've got a taste of the battle and recruiting systems, and there's a hamfisted moral alignment system in every game that leads to different endings which is neat.
I haven't played 5 yet, but the most entry level ones are probably the 3DS games, SMT 4 and SMT 4:Apocalypse, although people will insist starting with SMT 3 Nocturne which goes hard from the start. SMT 1+2 are pretty dated, but if you can get into it they're cool (save states are a godsend). There's also the side games like Strange Journey and Soul Hackers that play like SMT 1+2, and Digital Devil Saga that's a more traditional JRPG.
To add, there are some side-games and spin-offs that, while quite different from the mainline, can help you ease in if you like the genre (Raidou games for real-time ARPGs, the Persona games for urban fantasy/mystery high schooler JRPGs, Personas 3-5 for sim and dating mechanics, etc).
