Motivation: Many, me included consider Eyebite be cool, but mechanically very underwhelming spell for its level. So, let’s make it a balanced choice. Still, this question does not depend on if original version really is weak or not, this is only about this homebrew version.
The classes to consider as users of the spell: Bard, Sorcerer and especially Warlock, who needs to choose it as an Arcanum, the only and unchangeable 6th level spell they’ll have.
The other spells to consider as comparison points specially: Hold Monster (similar effect on target at 5th level already, for Bard and Sorcerer up-castable to 6th level for 2 targets) and then as actual 6th level aternatives, Mass Suggestion and Mental Prison (in XGtE so paywalled link), which also can be used to take enemies out of a fight, and for which Mass Suggestion has great utility use as well. There doesn’t need to be comparison against the original version of Eyebite. You can also compare to other spells up to level 6, if you think they’re relevant for the same role.
Goal of the homebrew: Eyebite should be an equal contender, when the character reaches the point where they can choose these spells.
Does this Enhanced Eyebite, description below, meet the above goal?
Casting Time: 1 Action
Components: V, S
Duration: Concentration, 1 hour
Attack/Save: WIS Save
For the spell’s duration, your eyes become an inky void imbued with dread power. One creature of your choice within 90 feet of you that you can see must succeed on a Wisdom saving throw or be affected by one of the following effects of your choice for the duration. On each of your turns until the spell ends, you can use your action to target another creature. If you target a creature again after it has succeeded on a saving throw against this casting of Eyebite, the creature has advantage on its saving throws.
Asleep. The target falls unconscious. It wakes up if it takes any damage or if another creature uses its action to shake the sleeper awake.
Panicked. The target is frightened of you. On each of its turns, the frightened creature must take the Dash action and move away from you by the safest and shortest available route, unless there is nowhere to move. If the target moves to a place at least 90 feet away from you where it can no longer see you, this effect ends.
Sickened. The target has disadvantage on attack rolls and ability checks. At the end of each of its turns, it can make another Wisdom saving throw. If it succeeds, the effect ends. If it fails, it takes 2d8 points of necrotic damage.
When cast at higher levels: The distance needed for Panicked effect to end increases by 10 feet for each level above 6th. The damage done by Sickened effect increases by 1d8 for each level above 6th.
Notes: Changes to original are highlighted for the benefit of those who know the original spell, even though comparison to original is not what I’m asking. The duration is increased to give this spell more utility, and ability to last for several encounters. The range is increased to match Hold Monster. The damage is added to Sickened effect, so it wouldn’t be strictly inferior to Panicked, which also gives the same disadvantages with different and arguable much stronger condition to end the effect. Scaling with level is added to keep the spell competitive at higher character levels. The ability to target same creature again is given so the spell doesn’t become useless if all enemies succeed at their saving throw, but disadvantage is given so that in most situation it’d still be better to do something else than keep spamming Eyebite at disadvantage.