As all the spells in Spell Law can be used in MERP (and some of these spells directly appear in the MERP books), it's fair enough to use them. And oh boy this has some impressive spells! Let's start with the most impressive of all; time travel. As part of Time's Bridge, the caster can travel back in time physically for a time, and potentially change the past. The other spells in Time's Bridge allow visions of the past and the future. Starlights meanwhile, allows for the manipulation of light for seeing and attacking (including focusing pre-existing moonlight and starlight into an attack).
Soul Destruction allows the caster to damage the very soul of their victim, including but not limited to body swapping, demonic possession, ripping out a chunk of the victims soul and ripping the victims soul out (abet temporarily). Fluid Destruction has spells which allow for the evaporation of up to 1,000,000 cubic feet of water and banishing rain.
Telekenisis allows for the use of telekenisis. Movement allows for being able to jump far, levitate, fly, merge with inanimate objects and pass through solid objects.
Controlling Songs allow the singer to control the target, from being friends to falling asleep to panicking to being afraid to being able to control them completely and even being able to kill them.
Detections allows for the individual to detect various things, such as hate, the invisible, magic, telepathy, evil, power and so on. Illusions allow the caster to cast illusions (of both sight and sound).
Invisibility allows the caster to become invisible and to make others invisible. Living Change allows the caster to change their own form or the form of others as well as to grow or shrink in size, as well as to analyse the form of another so as to change them or another.
Mind's Door allows the caster to teleport. Speed allows for spells that increase the casters speed and stamina.
Mind Visions allows the caster to read minds for force the target to answer a question or even steal the thoughts of others. Sense Through Others allows the caster to see and feel senses through an animal or another being.
Mystical Change allows the caster to become another person or creature, even as far as to create an entire persona and their true self falls into a slumber while the other persona takes over. Liquid Alteration allows for the manipulation of water, and even the transmutation of water into another liquid (so long as said liquid isn't magical).
Lofty Bridge allows for the teleportation of the caster and others, as well as flight, levitation, jumping & landing safely and opening portals in walls and barricading structures. Spell Enhancements allow for a spell to become stronger.
Mind Control allows the caster to mind control their victim, or outright breaking their mind. Sense Control allows the caster to control their targets senses, to the point of creating an illusionary world inside their mind which the caster has full control over.
Mind Mastery allows for the storing of memories and spells, protection against psychic attacks and mask their mental presence. Sense Mastery allows for the enhancement of the senses, such as being able to see to the horizon underwater, detecting illusions, merging their senses with someone else and more.
Mind Subversion allows for the subversion of the victims mind, such as turning them into a liar, a cheater, a thief, to become violent or even commit suicide. Mind Domination allows the caster to invade the minds of others, or have demons possess the intended victim, or even turn them into a zombie and torment their soul.
Mind Erosion allows the caster to erode their victims minds, causing them to become dulled or confused. Mind Death allows the caster to cause their victims mind to blank out and for them to forget their life experiences and memories (although this has a chance of backfiring on the caster too).
Gas Manipulation allows for the manipulation of gases, such as condensing water out of fog, controlling clouds and creating localised vacuums. Shifting allows the caster to alter their form so as to turn into someone else, water, mist or stone, as well as to breathe underwater and slip through small places like an octopus.
Self Healing allows the caster to heal themselves, and can fully regenerate their body (except for their brain) within 10 to 100 days. Spell Resistance allows for the caster to protect themselves from spells that seek to do physical and mental damage to them.
The introduction to this book even makes mention of MERP, and how the spells in Spell Law are compatable with it and the other roleplaying worlds of ICE.