To use ex-wild you need to get level to 50.
Then your Cards can be upgrated to level 105.
Level 100 give +5 to max level
Level 200 give +5 to max level

Base SED of 1 Mill give max level + 5 (not posible atm)
Base SED of 2 Mill give max level + 5 (not posible atm)
Base SED of 3 Mill give max level + 5 (not posible atm)

Finish stage 16-9 to get + 25 max levels. (Not posible atm).

N-Wild, R-Wild SR-Wild cant be used on Card with level 100 or greater.

N-Gacha, R-Gacha, SR-Gacha and spins can raise a Card to levels higher than level 100.

If a Card is level max level and a Gacha gives another copy of that the player get N-Wild/R-Wild/SR.wild.

Players should not spend Ex-wild on Cards that can be obtained from bonus stage or from N-Gacha.