I love the idea of a summoner class, I enjoy them so much! I'd like to see the character for this class as more cute-chibi like though to further surpass the stereotype of "evil overlords that summon minions". Maybe like a short little girl with a hot pink princess dress on, strawberry blonde hair, constant scared look on her face, white lace gloves, pink heels, and every time she summons something she gets all scared and these demons come to protect her xD
I'd like to see the same monsters in the game be used as the "tower types" for her, except with a slight discoloration change so the enemy and the ally monsters aren't confused between.
Both the ideas for the minion towers are great, and perhaps the summoner class could have both: Some of the towers can be placed in a confined area to be determined by the caster, and some tower types can be set to auto follow the caster. This would allow for a numerous amount of potential strategies.
I like the idea of the weapon being a book/tome, don't forget the pentagram that goes on it :p
I believe her standard attack should be a ranged one similar to the mage and monk's, due to the nature of her class.
Her sub-standard attack could be a melee attack that is extremely weak with a slow attack speed that stuns the single enemy she hits for 3/4ths the duration it takes for her to recover.
Her skillset: 1st skill: I like the healing idea, very useful as a necro/summoner
2nd skill: Something silly like a buff that she gets all scared and cries and gets a 2x speed boost and only receives 1/2 damage while in effect.