Level\combo skills

I was thinking it would be great to have combo effects in some skills, only activated when other skill is present or active. Example:

Summon : summons an spirit. If a command spirit and three other spirits are present, it casts Phantom flare (a nova like attack) around the command spirit and spirit boost. Else, it casts only spirit boost.

A level skill, in the other hand, is a skills that get added effects when leveled up. Example:

Storm level 10: summons a devasting storm. Unleashes a toxic\freezing\burning\electric cloud.

What do you think?