void tendrils … you can only kill them by single target spells ?!
Some things have to be targeted to get killed/destroyed, like shaman’s totems.
And explosive affix.
Check your interface>names>enemy units>minor (check it if it’s uncheck.)
Tentacles operate under the same ideas a totems, explosives, and pets. They must be single targeted and focused down. If they could die to AoE, they would never survive anything.