Improve tentacle summon with an on-hit grab

Made it immune to blind.
Taught it Use Tentacles on birth.
Gave it a nice balance of stats to inherit.
Made Visionary Combat talents auto-target for QoL.
Updated the Visionary combat description to include this, and also the gem gaze radius boost.
I've also coded a unique Tentacle Grab talent for this summon, but I don't think it's needed at the moment.