It will also kill him if he keeps using it, and Cell was not exactly trying until he got himself trapped. Any estimates on the force it was putting out because Madara has some pretty good durability with his Hashirama cells and substitution jutsu.
My speculation is based on the fact that the Genin have basic training on Genjutsu and he is two levels above that and is teaching... Is like saying an algebra professor has probably some knowledge of geometry...
How is a non offensive technique show better offensive strength? Meditation doesn't break Genjutsu, usually it takes someone else breaking it for them or at the very least somehow having foreknowledge of the attack.
[Yes and I think it might be obvious that someone who had meditated and trained their focus to the point of LITERALLY GROWING ANOTHER EYE might be somewhat resistant to mental attacks.
If its a matter of not getting caught in Genjutsu then we need to look at Gai more closely.
Why was Gai never put under Genjutsu by Madara?
Option 1: As he did with Itachi, Gai may have kept his vision on his feet as to avoid visual genjutsu. His mastery of martial arts could let him predict Madara's movements. Tien is one of the most advanced martial artists on the planet who, like goku can feel the presence of enemies through the displacement of air, sound and other such methods. So fighting without looking is a definite possibility.
Option 2: Gai was so fast and powerful that Madara had no opportunity to attempt to place him under Genjutsu. If this is the case then Tien rolf stomps.
Option 3: The specifications of the how 8 Gates works make the user immune to Genjutsu. If this is the case, Madara could pull this off.
Option 4: Genjutsu is unable to work on an opponent of major power. This is never stated and holds little sway but it would explain why almost every HAX genjutsu user can't just zap their powerful opponent to sleep. If this is true then Tien ROLF stomps.
This will be last time I post on this conversation but my verdict is Tien has the edge. Madara wins if we lowball Tien and wank to Madara hax.
The force of detailed objects being lifted early in naruto does give them an edge against dbs cast. How can you wonder about the idea when you see the Earth sound four members lift giant choji up with one arm! This puts madara in qualifying position of being a threat physically and not just because he have a hax power. He's above tien' prosperous realty of established showing of decorated ki blasts that are inadequate in heat and force (I don't think tien is as strong as base goku.). Just throwing terrifying perfectly airborne assaults (he has to see perfect!) of ki blasts can give madara the edge by using shadow clones or taking shelter in a forest or city. Out in the open, if tien have knowledge and madara doesn't use genjutsu, madara chances of winning becomes more difficult.