Is there any spell, item, or skill that allows a caster to maintain 2 concentration spells active at same time?
That would be unbalancing and run contrary to the entire reason for concentration spells. There are a number of ways to partially work around this limitation:
- Rings of spell storing and ioun stones of reserve can hold spells in them for later casting. Acquire one for an ally and cast a concentration spell into the item. Your ally will be handling the concentration when they activate the spell.
- As above, but give the magical item to your familiar.
- Sorcerers can use the twin spell metamagic to cast certain concentration spells on two targets instead of one.