This is a small idea I had for two modifier runes that would likely be Tier 2 or Tier 3 that is meant to add this feeling of "power" behind spells at the expense of casting time.
• When this modifier is applied it affects the entire spell.
• When casting a spell with this modifier on, the user has to 'charge' the spell like a bow.
What this does depends on whether it is the Power or Efficiency variant.
Power Variant causes the spell to gain up to 2 Amplify effects the longer it is charged, each boost raising mana cost 1.25x more than a raw Amplify Glyph (To account for your ability to variable increase damage rather than it being fixed). Each Power Variant modifier adds 2 more 'charges', to a total of 3 Glyphs for up to 6 whole Amplify effects when fully charged.
Efficiency Variant lowers the casting cost the longer it is held. Much like power it has 2 'charges'. Each charge lowers the base cost of the spell by 5% (calculated before accessories). This rune be stacked up to 3 times for up tp 6 charges for 30% reduction.
Each charge would take somewhere between 0.30 to 0.35 seconds to charge. And, if possible, there should be a very simple UI indicator around the crosshair to show the charges. Maybe a simple circle filling in clockwise with dots lighting up around the circle to indicate 'charges'.
Power and Efficiency are mutually exclusive for obvious reasons.
