As an Aran it's good to keep combo above 100 in order to do max DPS & Combo Drain/Combo Barrier being the same command, but different amounts of combo gets in the way of "strategy" at higher levels. Before a player has Combo Barrier, as long as they're on 30+ combos they can use drain whenever they would like. When a player has Combo Barrier it becomes a bit of a "nerf" to Combo Drain because you can't use it whenever you would like, you can only use it from 30-199 combo. If you're bossing & you're continuously Overswinging+Final Blowing, not breaking combo, then when you're at 200+ combo a boss dispels you, you can't use Combo Drain right away, you now have to use either Combo Barrier or Tempest one or more times in order to get under 200 combo in order to use Combo Drain.
I assume it would be very hard to program one of these skills to be a different button combination, so if that is not possible my suggestion is to make one of these two skills hotkey-able & take the combination input off of that skill.
Combo Fenrir vs Combo Tempest is similar, in some situations one skill is better, in other situations the other skill is better. Level 159 & below at LHC for example Tempest does 0 damage so if you accidentally go above 200 combo & try to Fenrir, you will instead do 0 damage. The best DPS at LHC for an Aran below 160 in my opinion is to get a high combo (enough that you can clear a platform with multiple Fenrir's) then use Fenrir a bunch. For example if after building combo you "4-hit" the mobs you'll want 400 combo, then use 4 Combo Fenrir's. Because of this I actually took the point out of Tempest as it ruins the fastest way to kill. If I were to then get into a Skele party I would want to put 1 point back into Tempest (or just accept that going the Fenrir route means I'm done Skeles entirely & will only train at LHC now). At a lot of bosses Tempest also isn't that good as the damage is does for 200 combo is not as good as the damage 2 Fenrir's would do with 200 combo, so it's better to have no points in Tempest to ensure you're always using combo's on Fenrir. Other times, like training at LHC 160+ you do want Tempest, but then the absolute "strongest" way to play would be to reset a point out of Tempest every time you go away from LHC & go bossing. Furthermore at stronghold in the future I assume that below a certain level you'll want to Fenrir there as Tempest won't work, so you'll want to build up combo then do a bunch of Fenrir's, the same way you would at LHC below level 160. By the time you're at Stronghold you'll likely have 30 points in Tempest as there aren't any places left to add points to, so resetting out of Tempest isn't really feasible, unless you just keep Tempest at Level 1 & keep using SP Resets daily.
My suggestion is to keep Combo Drain/Combo Fenrir on Down+Down+Attack & Side+Down+Attack respectively as they're used more often & it's fun to put in the combinations (especially Fenrir where you pick the direction, unlike Tempest which just does it's thing either direction). Put Combo Barrier & Combo Tempest on a hotkey the same way other skills are hotkeyed & the player can just press that button to use that skill, & it should only work if combo is over 200.
I assume it would be very hard to program one of these skills to be a different button combination, so if that is not possible my suggestion is to make one of these two skills hotkey-able & take the combination input off of that skill.
Combo Fenrir vs Combo Tempest is similar, in some situations one skill is better, in other situations the other skill is better. Level 159 & below at LHC for example Tempest does 0 damage so if you accidentally go above 200 combo & try to Fenrir, you will instead do 0 damage. The best DPS at LHC for an Aran below 160 in my opinion is to get a high combo (enough that you can clear a platform with multiple Fenrir's) then use Fenrir a bunch. For example if after building combo you "4-hit" the mobs you'll want 400 combo, then use 4 Combo Fenrir's. Because of this I actually took the point out of Tempest as it ruins the fastest way to kill. If I were to then get into a Skele party I would want to put 1 point back into Tempest (or just accept that going the Fenrir route means I'm done Skeles entirely & will only train at LHC now). At a lot of bosses Tempest also isn't that good as the damage is does for 200 combo is not as good as the damage 2 Fenrir's would do with 200 combo, so it's better to have no points in Tempest to ensure you're always using combo's on Fenrir. Other times, like training at LHC 160+ you do want Tempest, but then the absolute "strongest" way to play would be to reset a point out of Tempest every time you go away from LHC & go bossing. Furthermore at stronghold in the future I assume that below a certain level you'll want to Fenrir there as Tempest won't work, so you'll want to build up combo then do a bunch of Fenrir's, the same way you would at LHC below level 160. By the time you're at Stronghold you'll likely have 30 points in Tempest as there aren't any places left to add points to, so resetting out of Tempest isn't really feasible, unless you just keep Tempest at Level 1 & keep using SP Resets daily.
My suggestion is to keep Combo Drain/Combo Fenrir on Down+Down+Attack & Side+Down+Attack respectively as they're used more often & it's fun to put in the combinations (especially Fenrir where you pick the direction, unlike Tempest which just does it's thing either direction). Put Combo Barrier & Combo Tempest on a hotkey the same way other skills are hotkeyed & the player can just press that button to use that skill, & it should only work if combo is over 200.