Which is better stacking a skill or charging a skill? I'm not sure I understand the difference. For instance if i charge firefly to level five how is that different than casting it five times? Does it vary by skill?
For the majority of skills and spells, charging them will give them 20-25% more power per extra charge/stack, and cost less focus to cost. The difference between charging and stacking is not the one you seem to think (unless you just talked about two different scenarios in that same paragraph, if so, I'm sorry!) Stacking is the art of using your glyphs dynamically, and when you have multiple copies of the same glyph, you stack the as if you would stack cards from a deck of cards. This has the same effect as charging, but has fewer downsides. Here are the downsides to charging : - if you fizzle your cast, you need to recharge your spell from 0. - when you cast your ability/spell, you accumulate heat (the red cooldown that appears on your glyph). Heat makes the glyph cost more focus, the more heat you accumulated, the more focus the ability/spell will cost (so spamming it will make the focus cost get very high very fast). -Your cooldown for the glyph is longer after charging it than casting a single charge, meaning you have heat for a longer amount of time. When you dynamically stack, all these downsides can be ignored, only one glyph goes on cooldown, and for its regular duration indicated in the tooltip. The main downside of dynamically stacking is that if you don't pay attention, you can lose your stack, this can be avoided by casting mind lock, or adding a glyph to the soon to discard stack. major upsides to dynamic stacking is that you can stack multiple glyphs at the same time (I have videos where I would stack 3 to 4 different skills at the same time) and that you can stack even while under the effects of crowd controls (stuns, knockdown, etc).
https://sota.link/decks links to Dr. L's great playlist for deck building. There are a couple of videos in that focus on stacking or not. But the whole series is worth watching and revisiting once in a while.