[General] Hero spell limit?

[greenyaptec]

Hello, is there a limit, how much hero spells can hero have? i am trying to add another spell but i cant
I was wondering my hero will have 3 actives (hero spell), 1 passive (hero spell), 1 ultimate (hero spell), 1 unique (unit spell) and stat bonus (without icon, hero spell)

 

[rulerofiron99]

5.

The rest will have to be unit abilities, but you can make them look like hero abilities.

Replace the Hero Abilities icon with a Spellbook-derivative ability that opens up a list of "dummy" abilities; each of which when learned increases/adds a spell to the hero, and add dependencies.

EDIT: I think in this case the best would be to add stat bonus a different way, for example a merchant that sells a stat bonus item that consumes one hero skill point.