Tension boosts damage and healing power of attack,most skills and spells, early on before changing vocations it is best if you use it on martial artist since they can reach 20 tension in one turn if you get pschye up and use egg on, feel the burn(chance to raise tension if hit,excellent on tanks and solo players than gladiators imo), roar of tirade and luminary cdg raise tension by one and stun all enemies for one turn, tension boost raises tension to 50 or 100 on higher levels gladiator cdg,
Tension damage boost
Tension gets removed by disruptive wave, get knocked out, stun, sleep or paralysis.
High end skills like gigaslash, solar flair, should kill most bosses in the story or deal nice damage without any buffs if they are weak to the element
, high level spells like kafrizz have higher damage than weapon skills,All weapon skills and spells have caps so that tension isn't abused a few vocation skills can reach 9999 damage cap, have a ball and blind man's biff with fource at high strength or oomph or double up with ufb are a few of those skills.