I've just started a new campaign in second edition, which I'm also fairly new to. (I try to keep up with the books and reading but this is my first REAL game with the system)
As the title states, I've been attempting to create a conversion of the Cipher class from pillars of eternity (basically a Psychic Gish that builds energy [called focus] for spellcasting by dealing damage with weapons) for use in this campaign, but I'm having some difficulty converting some major portions of the class.
Base proficiencies and progression are simple enough, as this is, at a glance, an occult version of the Magus, to which end most of the proficiencies would likely match up (Master in Unarmed/Simple/Martial weapons, Master in up to Medium armor, and Master in Occult spellcasting.) Saves could be argued, and skills would likely be of a similar amount depending on the key ability score.
The challenge in my eyes starts with the first mechanic of the class, the Soul Whip. In the video game, Soul whip is a buff that applies to all your weapon attacks while you aren't at full focus, granting roughly 20% increased damage and converting a portion of your damage dealt directly into focus points, which are then spent to cast spells. Obviously the percent damage is right out, as that would just get annoying and the typical damage numbers in 2E don't justify it's use, but I'm not really sure what to use in it's place. There are a good number of class based damage buffs to draw inspiration from, but none of them is a perfect fit for the nature of the ability. Ideally it would be something that adds a noticeable but not overwhelming amount of damage to weapon attacks, that ideally would scale up the more damage your weapon dealt. The least mind-wracking idea I had here was a flat damage bonus that scaled with the number of damage dice your weapon dealt. This would keep damage fairly in line with other melee-type mechanics, and also provide a fairly direct way to generate the points for spellcasting, which could be as simple as "gain an amount of spell points equal to the damage dealt by your soul whip."
Next, and perhaps even more challenging, is the nature of the spellcasting itself. A "mana" system is quite separated from the way normal spellcasting is done in 2E, but I think the focus on spell levels as the scaler for spell power rather than caster level provides a fairly simple place to start; simply present a point cost for each level of spell (something like 5 per level, going from 5-50.) This system would preclude the use of actual spell slots, simply allowing for a highest level of spell as levels increased and likely working off a spell repertoire as an alternative form of spontaneous caster.
Another way to do this, and a way that perhaps appears more thematically coherent, is focus spells. Especially as focus points are a term used by both the class and 2e itself, trying to blend them together could certainly be an effective and efficient way to streamline the conversion, but not one that doesn't have its own issues. Focus spells, as written, don't really have a way to scale in the way cipher spellcasting is supposed to, as they automatically heighten to half your level and always cost 1 focus point each. In addition, trying to jury rig soul whip to generate 2e focus creates a whole wave of issues relating to focus spells from other classes now being rechargeable simply by hitting stuff. With all that in mind, focus spells seem like the wrong way to go.
There are absolutely more parts to the class to consider in converting, but these stood out to me as the most fiddly ones. If anyone has any advice or suggestions for making this, please let me know!