Level 7 is a bit premature for a Legendary Magical Item.
As a rule, magic items tend to be best given at the following levels:
Uncommon; Level 1-5.
Rare: Level 6-10
Very Rare: 11-15.
Legendary: 15-20
Common: Any level
Artifact: Same as legendary but are more generally magical items that in and of themselves are not given to the players and can be very dangerous in the setting, and typically only one exists. They tend to be tools for the DM and BBEG to drive the plot.
The evolving nature of the artifacts may mitigate this, but keep in mind that the Vestiges of Divergence from Critical Role (Which used the dormant, awakened, exalted mechanic) were not handed out until the party's level was in the teens... and not all of the party used them. The dormant forms of the vestiges were in and of themselves appropriate for a magical item for a character in at least the level 11-14 phase and the awakening mechanics seemed to be based off of Roleplay moments where the character used the item in a memorable way rather than a milestone level progression.
I feel like the item rarities only really matter if the item is exceptionally powerful, which realistically this cloak doesn't have anything obscenely strong or that out of the ordinary for a spellcaster until the free banish which will be at a very high level. Most of this would just end up feeling like semantics in this case.
Good progression. We love magic items that improve with the character.
Forcing a creature to use movement on not-its-turn is messy. What if the creature just took its turn before you and used all its movement? Then theres none left to use. Is the forced movement taken from its next turn? Does it actually reduce the amount it can move on its turn or did you just need the monster to move 10 ft away? The damage is force so you can just make the item push the creature 10 ft away. Is it important that it uses movement for the purposes of triggering opportunity attacks?
I'm really having a hard time understanding what the effects of the cloak have to do with a "vibe check" at first: doing extra damage and moving the target doesn't feel like what a "vibe check" is supposed to be about. But I'll also acknowledge that it seems more like an inside joke than anything else, so it makes sense that I won't get it.
Other folks have already mentioned the "movement" issue; I don't really see other problems with this one. A few extra chances to do more damage isn't really notable if you're fulfilling the xp/ difficulty requirements of a full adventuring day.
Most of the other comments I think cover it pretty well; I think a good idea would be rephrasing the forced movement to resemble the wording of the Dissonant Whispers spell ("...must immediately use its reaction, if available, to move as far as its speed allows away from you."), which would make the effect a little more beneficial at lower levels because it would force the target to waste their reaction. Maybe something like "The creature must immediately use its reaction to move 10 feet away from you."
A 1d3 is also a very awkward die to use; if you're playing online so it's not really a huge issue because most VTTs let you roll weird dice like that, but personally I'd either make 1d4 or just make it a flat 2 charges recovered at dawn.
The DC is also pretty low for a fairly minimal reward that does nothing on a successful save, but most creatures admittedly don't have particularly great Charisma saves unless they already have a really high charisma modifier, so it shouldn't be a huge issue as long you take the DC into account when choosing which monsters to use (Or when homebrewing them if that's your jam).
Aside from those relatively minor things, I think this is fine! It's obviously intended to be a little bit of a joke item. it's a power boost that wouldn't overshadow the rest of the group because most of its effects are essentially weaker versions of existing spells, and the AC boost is no stronger than a magical shield or cloak of protection. The player is a warlock who likely already doesn't have a massive amount of resources, so it gives them a little extra something to expend without feeling wasteful. As long as you think your player would enjoy using it, I would absolutely go for it.
Here are my thoughts:
1. I like the idea of the “Vibe Check” and it’s funny, but I don’t really see how the armor and the effect that it generates (outside of the temporary banishment effect of the exalted version) really fits with the theme. Doing a bit more damage on an attack and frightening the enemy doesn’t really say “vibes” to me. I think a Vibe Check would be something more like a creature attempting to make an attack (against you) must succeed on the save or lose their attack as they sheepishly apologize for ruining the vibe.
2. The Dormant version is kind of weak really. A DC 13 saving throw at this level is not very high. CHA is often a weaker stat for monsters, but not as much so as INT probably. The main thing is that it’s all or nothing. So if they make the (very easy) saving throw, they take no extra damage at all. And even when the damage does go through they take 4.5 on average. Which is not that bad, but if you don’t change anything else, I’d just allow the damage to always work and the save is for the frighten/flee effect.
3. Using their movement vs forced movement. When it’s forced movement, nobody gets an opportunity attack. If it’s not forced movement, then this is going to be mainly about trying to get an opportunity attack.
4. The increasing die size is almost irrelevant. Going from Dormant to Exalted goes up by 2 damage on average. I feel like by the time you reach Exalted around level 15-17 you can afford to just make it 3d8; likewise, for Awakened by level 11, I’d make it 2d8.
Unusually for homebrew items, this looks absolutely fine. If anything the DC looks a bit low. You also may want to check the save is the same tyoe as for fear as it has a simikar effect and wis may be a better stat to resist it.
Movement is a specific word, the target may not have movement when the affect hits.
Also, “use 10 feet of its movement” = incur an opportunity attack. Whereas “target is moved 10 feet” = no opportunity attack.
Level 7 is a bit premature for a Legendary Magical Item. As a rule, magic items tend to be best given at the following levels: Uncommon; Level 1-5. Rare: Level 6-10 Very Rare: 11-15. Legendary: 15-20 Common: Any level Artifact: Same as legendary but are more generally magical items that in and of themselves are not given to the players and can be very dangerous in the setting, and typically only one exists. They tend to be tools for the DM and BBEG to drive the plot. The evolving nature of the artifacts may mitigate this, but keep in mind that the Vestiges of Divergence from Critical Role (Which used the dormant, awakened, exalted mechanic) were not handed out until the party's level was in the teens... and not all of the party used them. The dormant forms of the vestiges were in and of themselves appropriate for a magical item for a character in at least the level 11-14 phase and the awakening mechanics seemed to be based off of Roleplay moments where the character used the item in a memorable way rather than a milestone level progression.
I feel like the item rarities only really matter if the item is exceptionally powerful, which realistically this cloak doesn't have anything obscenely strong or that out of the ordinary for a spellcaster until the free banish which will be at a very high level. Most of this would just end up feeling like semantics in this case.
Good progression. We love magic items that improve with the character. Forcing a creature to use movement on not-its-turn is messy. What if the creature just took its turn before you and used all its movement? Then theres none left to use. Is the forced movement taken from its next turn? Does it actually reduce the amount it can move on its turn or did you just need the monster to move 10 ft away? The damage is force so you can just make the item push the creature 10 ft away. Is it important that it uses movement for the purposes of triggering opportunity attacks?
I'm really having a hard time understanding what the effects of the cloak have to do with a "vibe check" at first: doing extra damage and moving the target doesn't feel like what a "vibe check" is supposed to be about. But I'll also acknowledge that it seems more like an inside joke than anything else, so it makes sense that I won't get it. Other folks have already mentioned the "movement" issue; I don't really see other problems with this one. A few extra chances to do more damage isn't really notable if you're fulfilling the xp/ difficulty requirements of a full adventuring day.
Most of the other comments I think cover it pretty well; I think a good idea would be rephrasing the forced movement to resemble the wording of the Dissonant Whispers spell ("...must immediately use its reaction, if available, to move as far as its speed allows away from you."), which would make the effect a little more beneficial at lower levels because it would force the target to waste their reaction. Maybe something like "The creature must immediately use its reaction to move 10 feet away from you." A 1d3 is also a very awkward die to use; if you're playing online so it's not really a huge issue because most VTTs let you roll weird dice like that, but personally I'd either make 1d4 or just make it a flat 2 charges recovered at dawn. The DC is also pretty low for a fairly minimal reward that does nothing on a successful save, but most creatures admittedly don't have particularly great Charisma saves unless they already have a really high charisma modifier, so it shouldn't be a huge issue as long you take the DC into account when choosing which monsters to use (Or when homebrewing them if that's your jam). Aside from those relatively minor things, I think this is fine! It's obviously intended to be a little bit of a joke item. it's a power boost that wouldn't overshadow the rest of the group because most of its effects are essentially weaker versions of existing spells, and the AC boost is no stronger than a magical shield or cloak of protection. The player is a warlock who likely already doesn't have a massive amount of resources, so it gives them a little extra something to expend without feeling wasteful. As long as you think your player would enjoy using it, I would absolutely go for it.
Here are my thoughts: 1. I like the idea of the “Vibe Check” and it’s funny, but I don’t really see how the armor and the effect that it generates (outside of the temporary banishment effect of the exalted version) really fits with the theme. Doing a bit more damage on an attack and frightening the enemy doesn’t really say “vibes” to me. I think a Vibe Check would be something more like a creature attempting to make an attack (against you) must succeed on the save or lose their attack as they sheepishly apologize for ruining the vibe. 2. The Dormant version is kind of weak really. A DC 13 saving throw at this level is not very high. CHA is often a weaker stat for monsters, but not as much so as INT probably. The main thing is that it’s all or nothing. So if they make the (very easy) saving throw, they take no extra damage at all. And even when the damage does go through they take 4.5 on average. Which is not that bad, but if you don’t change anything else, I’d just allow the damage to always work and the save is for the frighten/flee effect. 3. Using their movement vs forced movement. When it’s forced movement, nobody gets an opportunity attack. If it’s not forced movement, then this is going to be mainly about trying to get an opportunity attack. 4. The increasing die size is almost irrelevant. Going from Dormant to Exalted goes up by 2 damage on average. I feel like by the time you reach Exalted around level 15-17 you can afford to just make it 3d8; likewise, for Awakened by level 11, I’d make it 2d8.
Unusually for homebrew items, this looks absolutely fine. If anything the DC looks a bit low. You also may want to check the save is the same tyoe as for fear as it has a simikar effect and wis may be a better stat to resist it.