With the help of an online calculator specifically tailored toward combination calculations, and assuming that a character will only use an average of 2~3 skills, that's an average skill combination of about 700 in variety. That may seem like a lot, but then you should also factor in that plenty of skills will seem a lot less effective together than others. Who's going to use a Meelee warrior with Static Touch? Probably not many.
One way to increase the variety without adding more skills or making things too much more confusing than they are, is to add a bit of polymorhpism to the skills. In many great spellcasting games, there are usually abilities called "Quick Spell", where usually the damage is less but the spell is cast much more quickly. The opposite of quick spell would be something like "Focused Spell" where more time and energy is put into the spell for a greater result. Another interesting type of "Spellcasting" is where the spell is split into multiple parts, or doubles/triples at a slightly decreased cost (If double, then 195% instead of 200% cost) and so on.
This type of Polymorhpism can also apply to meelee skills, where a quickcast of Heroic Slam could make hitting that Furious Giga Slime slightly easier. While a quicker Whirlslash may allow for a quicker knockback, stopping those quicker monsters from hitting in the middle of the skill. Most of the polymorphism would be some sort of animation/casting increase, and could be applied to an object quite easily. If the character happens to have x amount of points into these abilities, they'd be able to choose to toggle these kinds of abilities and have quite the amount of options. "Should I go with a slower Heroic Slam and try to half Giga Slime's HP in Arcade mode in one fell swoop, or go for multiple attacks of the skill and hope to do more/less with crit damage potential?".
The toggle of these types of polymorphs of the abilities doesn't have to be limited to "All your abilities are quickcasted" either. Each ability could have a little toggle indicator as to whether it's normal, multiple, quickcast, or focus cast. Then a new player could see these toggles and learn over time how they impact their abilities. This would give an even greater range of choices in how their play style feels, while still keeping the learning curve relatively low.
One way to increase the variety without adding more skills or making things too much more confusing than they are, is to add a bit of polymorhpism to the skills. In many great spellcasting games, there are usually abilities called "Quick Spell", where usually the damage is less but the spell is cast much more quickly. The opposite of quick spell would be something like "Focused Spell" where more time and energy is put into the spell for a greater result. Another interesting type of "Spellcasting" is where the spell is split into multiple parts, or doubles/triples at a slightly decreased cost (If double, then 195% instead of 200% cost) and so on.
This type of Polymorhpism can also apply to meelee skills, where a quickcast of Heroic Slam could make hitting that Furious Giga Slime slightly easier. While a quicker Whirlslash may allow for a quicker knockback, stopping those quicker monsters from hitting in the middle of the skill. Most of the polymorphism would be some sort of animation/casting increase, and could be applied to an object quite easily. If the character happens to have x amount of points into these abilities, they'd be able to choose to toggle these kinds of abilities and have quite the amount of options. "Should I go with a slower Heroic Slam and try to half Giga Slime's HP in Arcade mode in one fell swoop, or go for multiple attacks of the skill and hope to do more/less with crit damage potential?".
The toggle of these types of polymorphs of the abilities doesn't have to be limited to "All your abilities are quickcasted" either. Each ability could have a little toggle indicator as to whether it's normal, multiple, quickcast, or focus cast. Then a new player could see these toggles and learn over time how they impact their abilities. This would give an even greater range of choices in how their play style feels, while still keeping the learning curve relatively low.
It adds a lot of extra DPS with very little casting, and the Silver+ Charge can stun enemies. A great synergy. Even moreso if you combo that stun with Insult To Injury.