Persona 5 Strikers will have you leveling up and combining your Persona together in the Velvet room much like in the original Persona 5. Also like Persona 5 you will be given requests throughout the main quest that will require you to get access to a specific Persona. This is normally some combination of getting a Persona, but also getting it with a skill that it would need to inherit from another. This could mean a lot of trial and error.... or you can just take a peek below and get back to slaying Shadows.
Title: Prison Mail, Part 1
To-Do: Show Archangel with Amria Drop to Lavenza
Note: Fuse Succubus and Andras to receive Hua Po. Hua Po and High Pixie at level 14 can be fused together to create Archangel with Amrita Drop.
Title: Prison Mail, Part 2
To-Do: Show Eligor with Divine Grace to Lavenza
Note: You can fuse together a Lamia and Orthus to get Ame No Uzine. Level Ame No Uzine up to level 29 and they will learn Divine Grace. Fusing Ame No Uzine with Lilim will create Eligor. To get my Ame No Uzine from level 23 that it is created at to 29 took a bit over 33k pp.
Title: Prison Mail, Part 3
To-Do: Show Kaiwan with Makouga to Lavenza
Note: Fuse a lv 26 Setanta with a lv 27 Principality, at this point it’s likely that you currently have these Personas in your possession/registered.
Title: Prison Mail, Part 4
To-Do: Show Mitra with Regenerate 1 to Lavenza
Note: When Setanta reaches level 31 it will learn Regenerate 1. Fuse the Setanta with a Lv 27 Principality and ensure it inherits Regenerate 1.
Title: Prison Mail, Part 5
To-Do: Show Unicorn with Zionga to Lavenza
Note: Another simple fusion quest, this time you’ll fuse a Black Ooze Lv. 33 with Shiisa Lv. 35 and make sure Unicorn inherits Zionga. You’ll now be able to raise the max skill level for Joker’s Wild.
Title: Prison Mail, Part 6
To-Do: Show Queen Mab with Technical Adept to Lavenza
Note: Level up your Kaiwan to 37, it will already have the Technical Adept skill but it needs to be at this level for the fusion. Combine Kaiwan and a Lv. 40 Kikuri-Hime and make sure that Queen Mab inherits the Technical Adept.
Title: Prison Mail, Part 7
To-Do: Show Trumpeter with Diarahan to Lavenza
Note: Once you level up Norn to 54 he will earn the required skill, at that point fuse them with a Lv. 48 Sarasvati to get Trumpeter. Make sure that Trumpeter inherits Diarahan.
Title: Prison Mail, Part 8
To-Do: Show Cu Chulainn with Concentrate to Lavenza
Note: Cu Chulainn with Concentrate can be fused from a Lv. 59 Mot and a Lv. 55 Nebiros. When you first fuse Mot it will be at level 57 so you’ll need to level it up twice to get Concentrate before proceeding.
Title: Prison Mail, Part 9
To-Do: Show Dominion with Nuke Amp to Lavenze
Note: With Mot, probably the same one you used in the previous Prison Mail request, level him up to Lv. 62 so that they get the Nuke Amp skill. Then fuse it with Forneus at Lv. 60 to create Dominion.