Stay really close to Tiger Vanguard cause backing away makes him do those nasty tornado attacks with the blood. The best way to handle his lunges is to dodge toward his back right when you see him start the animation, this lets you avoid damage and get some hits in while hes recovering. For the air attacks wait a bit before dodging cause most players mess up by dodging too early and the tracking will catch you. Cloud Step is good to have but its actually better for avoiding his sword attacks than the lunges, maybe interesting that lots of players waste it on the wrong moves.

Keep your stamina above 30% at all times, and dont even think about using Spirit Summons they just make the fight harder. The biggest thing players mess up is trying to parry the lunge but the window is way too tight, just focus on dodging first and youll get the counter timing down later. Remember to stay close to him, cause if you let distance build up he starts doing those really annoying ranged attacks that are much harder to deal with. When he tries making space just follow him and keep the pressure on, this way you control which attacks he uses and avoid the worst ones.