I love the idea for better summon spells. Here are some ideas:
Either 1, there could be a Greater Summon Spell which summons Dragons, Lich Lords, etc. at FULL STRENGTH. However...there is only a one in three chance of summoning an obedient one. If you are unlucky the summoned monster immediately turns on the caster. Something that can produce a nice result, but also a bad one.
OR
There could not be a summon spell, but a Control spell. You would have to go to the lich lord room and cast the spell on a lich lord, and then you can control it for a while. After maybe 1 minute you have to control it again, or it will turn on you. Same with drags, etc.
The above spells could be made even more cooler if instead of treating the summoned or controlled creature as a pet, your soul gets transfered to the creature, and you can walk around as it and cast its spells etc. Haven't you always wanted to be an elder gazer? However, your mage character is stuck without anyone in him - ie he is frozen so it is very easy to kill him. Perhaps with the Control spell, as soon as you control a creature, your mage is transported to some place in Bucs Den, so you need friends to protect you while you are out in your new Shadow Wyrm..