Add to the control gravity ability:Crius can increase the weight of objects at will, and he can make things weightless. He is able to make any one non-living object too heavy to lift for a period of 1-4 melee rounds; this power can be increased to permanency if the titan is allowed to work on the object for one full turn (saving throw vs. the permanency applicable).
Perhaps we could say that the armor-check penalty of armor is doubled in the gravity field?In battle, the titan creates a field of gravity that causes anything launched at him of a physical nature (arrows, spears, etc.) to fall short. All attackers will be at —4 on their chances to hit and —1 on their armor classes while in this field. Likewise, dexterity bonuses do not apply.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.