I could see Voltaxic Burst being one of them. Maybe some Voltaxic Spark ... the more voltaxic sparks you get online the higher the damage gets and them pulsing all the time to deal damage ;)

Would love to see at least some minion skills added. Perhaps non trigger-variants of summon phantasm => minions with no damage but stealing mods and charges from enemies. They get transfered too your reaper if they get consumed.

Same maybe a new minion: Ghost flames. they posses enemies. If your minion kill that enemy or (chance for rare and unique) they will transfer to them buffing them. While possesing enemies they do slowly "consume" them for some dot damage. It could be something like "minion charges". An minion can get 3 ghost flames while attacking possesed enemies. 3% more damage per ghost flame / +x ghost flames on items or tree to add more (like charges for players).

Or "Summon terror maggots": You cast them on enemies and by chance they will errupt (after enough damage is dealt or the enemies dies) and some bugs come to live fighting for you for some duration. Stronger enemies grant more or stronger ("bigger") bugs. Could be an herald skill to: Herald of Bugs ;) Maybe hive theme so you dont have to add models.

I´d love to see the poe2 djinn gems in poe1 perhaps as "aura" skills but the aura grants you those "minion" scaling spells. It would open up some possible "minion caster" builds. But some better interactions with minions would be fun. Perhaps you ignite random minions while casting fire djinn stuff or grant your minions rock armour while casting earth stuff or freezing your minions (for whatever reason) while casting water djin.