Inner Passion is a passive ability introduced with the 6th Generation of Honor Units:
Each 5* Inner Passion Unit increase this level by 2, while 6* units increase the limit by 5. The limit without related pets is 100. This can be reached using only a single unit or a mixture of them all.
Upon reaching 5*, the Pets for the 4 Inner Passion units increase the maximum Limit of Inner Passion. The 4 pets in question are:
Each pet allows it's Hero Couple (when evolved to 6*) to increase the Limit of Inner Passion by 5. This this increase is limited to 50 for each individual unit so 10 of each unit, seniored to 6*, is required.
With 10 seniored version of each unit the actual value of Inner Passion will be +200 (short of the limit of 300). To reach this any combination of 5/6* units can be used:
- 50 5* units
- 20 6* units,
- 20 5* units and 12 6* Units
TLDR - To maximise Inner Passion the 4 Pets (Windy, Dark Snake, E-77 and Seahorse) must be 5*, 60 total Senior Units of the Hero Couples (Sylphid, Medusa, Steam Punk and Naga) are required, with a minimum of 10 of each unit.