Risking a third attack shouldn't even be on his mind at all since his flesh blood and bones would be used instead to power up the rune. At that moment, he might actually truly die.
But then an idea suddenly came into Tron's mind.
With the System, his cells adapts to any level of damage his body receives as long it doesn't kill him. Which meant his body grows stronger the more devastating the damage he receive is.
And generally, the rune possess roughly the strength of a Rank one magus. Which meant that once the arcane energy within is flesh has been drained by the rune, his body would be drained off which would deal damage equivalent to a rank one magus attack to his flesh, improving his strength in the process.
Using this hack, he would actually be able to increase his strength in another way instead of depending directly on the daily quests and battle.
"BANG!"