I came up with some magic powers, and wanted to solicit comments on them.

Blood Magic [-1]
Description: You give your lifeblood as a sacrifice to fuel your magic.
Musts: You must have thaumaturgy, evocation, sponsored magic, or some other form of magical ability.
Skills Affected: Conviction
Effects:
Power in the Blood: You may spend physical stress to cast a spell or to add power to a spell just as you would mental stress.
Deep Hurting: You may also take physical consequences to fuel magic, as you would mental consequences. These consequences add power at 1 and 1/2 times their normal value, but may not benefit from any regeneration powers or magical healing on consequences you get that power bonus from. The Blood Drinker vampirism power clears minor consequences as usual.

Magic Mimicry [-1]
Description: You can copy any magic spells you see in action.
Musts: You must have thaumaturgy, evocation, sponsored magic, or some other form of magical ability. Sponsored magic grants certain bonuses as part of its cost, and that may include this power as a large part of it.
Skills Affected: Conviction, Discipline, Lore
Effects:
Magus See, Magus Do: This acts similarly to refinement that gives you access to a new element, only instead of that element you can cast any spell you've seen done before, even if you only saw it once.

Aquatic Caster [-1]
Description: Your magic is in tune with water and is not disrupted by its flow.
Musts: You must have thaumaturgy, evocation, sponsored magic, or some other form of magical ability. Sponsored magic often grants unique bonuses, and this may be one of them.
Skills Affected: Conviction, Discipline, Lore
Effects:
You can cast magic on water, from underwater, or through flowing water without difficulty. If you have any senses that work underwater, you may cast magic on any target you can sense in that way, even when murky or deep water obscure normal sight.

Signature Spell [-1]
Description: You have a single spell that you can perform better than any others.
Musts: You do not need to have other magical abilities, but if you do the bonuses from this power stack with any bonuses you get from them.
Skills Affected: Conviction, Discipline, Lore
Effects:
Favorite Spell: You gain +2 control and +1 power or +2 power and +1 control (choose which when you take the power) to a single spell. If you have no other magical abilities, then this is the only spell you can cast.