A skill that you can summon random mobs just like the summoner would be very fun, like:
Level 1 Book: Cost 50 myst, have 25% chance of summonig a friendly mod who will defend you from attakers, and 75% chance to summonig a aggressive mob who will attack anything in its way.
Level 2 Book: Cost 100 myst, 50% friendly and 50% aggressive
Level 3 Book: Cost 200 myst, 75% friendly and 25% agressive
The summoned mob will stay in the place you summoned him until someone slay him or you use the skill again, he will not fallow his summoner. If the summoned mob is the friendly tipe he wont attack until he is attacked or his summoner was attacked on his view. If the mob is the aggressive tipe he will attack anything close to him.
What you guys think about this ideia?