Catechumens were normally, as part of church procedure, baptized in times of emergency persecutions. They were still called catechumens because they had not finished their classes and had not formally entered the church during Easter/Pentecost. But they were baptized. This is a fact.
It is also fact that we have Saints in the official martyrology who have been venerated for 1700 years BECAUSE THEY WERE BAPTIZED IN THEIR OWN BLOOD.
As an example, Saint Emerentiana is clearly told by Tradition passed down for more than 1700 years to have been baptized in her own blood.
Can you explain to me how can someone do an act of martyrdom WITHOUT the theological virtues necessary to motivate such an act?
ST IIa-IIae, q. 124, a. 2, ad 2 :
« Ad actum martyrii inclinat quidem caritas sicut primum et principale motivum, per modum virtutis imperantis, fortitudo autem sicut motivum proprium, per modum virtutis elicientis. Et inde etiam est quod martyrium est actus caritatis ut imperantis, fortitudinis autem ut elicientis. Et inde est quod utramque virtutem manifestat. Quod autem sit meritorium, habet ex caritate, sicut et quilibet virtutis actus. Et ideo sine caritate non valet. »
"Charity inclines one to the act of martyrdom, as its first and chief motive cause, being the virtue commanding it, whereas fortitude inclines thereto as being its proper motive cause, being the virtue that elicits it. Hence martyrdom is an act of charity as commanding, and of fortitude as eliciting. For this reason also it manifests both virtues. It is due to charity that it is meritorious, like any other act of virtue: and for this reason it avails not without charity."
ST IIa-IIae, q. 124, a. 2, obj. 2 :
« Ad martyrium praecipue inclinat caritas, unde in quodam sermone Maximi dicitur, "caritas Christi in martyribus suis vicit." Maxime etiam caritas per actum martyrii manifestatur, secundum illud Ioan. XV, "maiorem dilectionem nemo habet quam ut animam suam ponat quis pro amicis suis." Sine caritate etiam martyrium nihil valet, secundum illud I ad Cor. XIII, "si tradidero corpus meum ita ut ardeam, caritatem autem non habuero, nihil mihi prodest." »
"Charity is the chief incentive to martyrdom: Thus Maximus says in a sermon: 'The charity of Christ is victorious in His martyrs.' Again the greatest proof of charity lies in the act of martyrdom, according to Jn. 15:13, 'Greater love than this no man hath, that a man lay down his life for his friends.' Moreover without charity martyrdom avails nothing, according to 1 Cor. 13:3, 'If I should deliver my body to be burned, and have not charity, it profiteth me nothing.'"
ST IIa-IIae, q. 124, a. 3, corpus :
« Martyrium autem, inter omnes actus virtuosos, maxime demonstrat perfectionem caritatis. Quia tanto magis ostenditur aliquis aliquam rem amare, quanto pro ea rem magis amatam contemnit, et rem magis odiosam eligit pati. (…) Patet quod martyrium inter ceteros actus humanos est perfectior secundum suum genus, quasi maximae caritatis signum, secundum illud Ioan. XV, "maiorem caritatem nemo habet quam ut animam suam ponat quis pro amicis suis." »
"Of all virtuous acts martyrdom is the greatest proof of the perfection of charity: since a man's love for a thing is proved to be so much the greater, according as that which he despises for its sake is more dear to him, or that which he chooses to suffer for its sake is more odious. (…) It is clear that martyrdom is the most perfect of human acts in respect of its genus, as being the sign of the greatest charity, according to Jn. 15:13: 'Greater love than this no man hath, that a man lay down his life for his friends.'"