Exploiting time stop

[J-H]

Time stop has quite a few limitations. What's the best way a player character could exploit an item that gives access to Time Stop once per day for a 2 round duration?

What spells, aside from Delayed Blast Fireball and summoning minions, are best to use during Time Stop?

[Theaitetos]

Anything that affects merely the battlefield, or that affects enemies only on the beginning of their turn, e.g. Prismatic Wall, Maddening Darkness, Blade Barrier, Cloudkill, Sickening Radiance, Evard's Black Tentacles, Stinking Cloud, Spirit Guardians, Sleet Storm, Web, …

[kazaryu]

Time stop has quite a few limitations. What's the best way a player character could exploit an item that gives access to Time Stop once per day for a 2 round duration?

What spells, aside from Delayed Blast Fireball and summoning minions, are best to use during Time Stop?

It depends entirely on who its given to. Clerics/druids could actually do a decent bit as far as healing/self buffs with 2 instant turns. Wizards would have a harder time, but are more likely to use the time to do things that would generally otherwise use multiple turns (pop a couple of defensive buffs, throw up a wall, thhings ofnthat nature)

Beyond that most nonmagical characters would tend to have little use for it beyond as a repositioning tool, although it could be argued that a martial could use it to gain advantage on an attack....realistically even an auto crit. But thats pretty dm dependent. (But also imo not really all that powerful considering its a 9th level spell)

Edit: TL:DR it kinda depends on what type of character gets it. I

[MrStabby]

What level are we talking about here? Spells like mordenkeinen's faithful hound and wall of force spring to mind as a relatively low level tool..

[J-H]

The Mummy Lord who casts it against them will have 5th level and below spells available, as he's using his 6th level slot to fight them (possibly repeatedly) with Simulacrum on the way to his lair. His best spells unless I change his list around more are Contagion (not compatible), Insect Plague (maybe compatible), and Guardian of Faith. I suppose he could also cast Silence on a stone, put it down, and then have one of his minions pick it up after Time Stop is over, but that's a bit fiddly.

I may just give him some good healing potions. The party will be low-ish on potions by then and need to restock anyway.

The party will hit level 12 when he is defeated, and still have several battles to go. Life cleric, Fire sorc, Barbarian, Kensei, 2x Arcane Trickster.

If it's super over powered, I would want to nerf it for the sake of any play that occurs after the campaign.