To be honest with you, the type of RPG combat that would port to IF the most faithfully would be turn-based JRPG combat, in particular similar to styles found in Final Fantasy 1 through 10-2, and countless other JRPGs.
The combat involves the navigation of menus, and even when selecting the target of an attack or a healing spell, the older games included a small menu list of available targets instead of moving a cursor between on screen targets. Even all the relavent in-battle messages were communicated in text, including dialog, whether or not an attack missed, damage dealt, etc, etc. Even the end of the battle would announce items won, experience garnered, and any new abilities learned, all in text.
The only thing that would need to be translated into text is the description of the enemies and the attacks and spells themselves.
I’ve actually been chewing on a Final Fantasy VIII port to Inform or TADS. It would follow all the same characters and plot beats of the original game, but it would be all text, making it more accessible to a wider audience. Additionally, I wanted to leverage the strengths of IF and cheap text, by allowing more branching than the original game. For example, there’s a part of the game, where Squall and company are rushing to unlock a defensive secret deep in Balamb Garden to help prevent eminent destruction by incoming Galbadian missiles. The problem, is the urgency is manufactured. You can take as long as you wish, hours, days even, and, as long as you don’t die, the missiles never arrive. It removes the suspence and also shows the writer’s unwillingness to allow actual failure without a game over screen. If I were to port this, I would allow Squall and Company to potentially fail in this effort, and, more importantly, allow them to live with the consequences.
Here's an example of allowing a failure state to play out:
Squall and company fail to activate the secret of Balamb Garden in time and Balamb Garden is destroyed by Galbadian missiles. While Squall and company are protected by being deep underground at the time of the strike, and other party members are off-site having attempted to prevent the missile strikes in the first place, a number of important characters would be killed in this event, including Cid, the headmaster, virtually the entire student body and faculty, and Elone, who was hiding in the Garden, unbeknownst to Squall at the time.
The world of Final Fantasy 8 would be thrown into chaos. Not only would the loss of the powerful institution leave a void in the fight against the sorceress Edea and her malevolent ambitions, but the sorceress’ unintentional murder of Elone would stymie her plans as well.
Squall and company are left scattered and desperate. The main characters are all left to fend for themselves in a world now under Galbadian control. They must navigate the dangerous landscape while dealing with their emotions and uncertainty.
The group forms a resistance to counter Galbadia’s rule and to locate any remnants of Balamb Garden’s survivors. They become part of an underground network of rebels, working to expose Galbadia’s atrocities and liberate oppressed regions.
Without Balamb Garden’s intervention, Edea’s tyranny becomes more pronounced. She extends her control over nations and tightens her grip on the world. She razes Timber to the ground in retaliation for partisan activity.
Sorceress Ultimecia, who is controlling Sorceress Edea from the future, is forced to find a new strategy, with Elone dead. So, she sets her sights on freeing Sorceress Adel from their orbital prison so she can consolidate control over both Esthar and Galbadia, which would allow her to redirect the formidable combined resources and tech of both nations towards finding another way to replicate Ellone’s powers. (As Dr. Odine of Esthar was researching this to begin with before the capture of Sorceress Adel)
This results in Sorceress Ultimecia taking control of Rinoa in a similar plot to the original game, freeing Sorceress Edea.
Sorceress Edea is a more broken woman in this scenario, as she had directly caused the deaths of her husband, Cid, and her adopted daughter, Ellone. Rather than seeking out a way to remove her powers, she chooses, in her grief and guilt, to instead to go on a suicide attack on Galbadia, and attacks Deling City with her formidable powers, gutting much of the city and leaving a significant power vaccum in Galbadia. Rinoa’s father, General Caraway, conflicted between destroying the regime that controlled Galbadia and protecting its people from harm, sets off hidden explosive charges buried under the Presidential palace, hidden there as an insurance policy by former paranoid president Vinzer Deling to decapitate a possible coup, killing Sorceress Edea and demolishing the center of government and the symbol of power for Galbadia.
This intense power vacuum sets up a multifaceted civil war waged by competing Galbadian Generals and Admirals turned warlords.
And so on…
Ostensibly, I would still allow the player to possibly play through the game in the canon manner, but allow divergence in places where I feel AAA budget and time constraints for what was an enormous game at the time preventing needed variance and exploration.
Anyway, back to my original point, from a combat standpoint, I feel turn-based JPRG combat loses the least of its essence when translated into text only IF.
(ETA: Just realized I accidentally put out an additional pitch beyond what I was already doing, lol. Whoops. Ideas are cheap.)