Roberto has sheathed his sword and grips the Trident, surprised and enraged when Attuma resists him.
Strength +2, Weary -1, equals 1+ a die roll
Roll to seize the Trident!: 1D10+1 = [7]+1 = 8
He wrenches the Trident of Poseidon from the fiends grasp!
Then Roberto notices Attuma mutter incantations of power, so it is a matter of self defense, and he stabs down to slay his foe once and for all.
Quick +1, Trident +3, Weary -1, equals 3 + a die roll
Initiative: 1D10+1+3 = [5]+3 = 8
Roberto exerts himself again, shouting as hie strikes and spending Fatigue
Saint James guide my hand!
Dex +1, Single Weapon 6, Trident +3, Exertion +6, Weary -1, equals 15 plus a die roll
Attack roll, spending Fatigue: 1D10+15 = [1]+15 = 16
exploder: 1D10 = [3] = 3
so (two times 3) plus 15 equals 21.
Attuma had a Defense of 1? It should be -2 without the trident. Attack Advantage 23. Plus Strength +2 and Trident +5 equals Incoming Damage +30.
Not sure what extra bonuses, if any, this trident has. Using the basic stats from Lords of Men.
If he is yet conscious, Roberto will try to Fast Cast a Spell
Fast Cast Speed: Quick +1, Finesse 3, Tired -3, equals 1 + a die roll
Fast Cast Speed: 1D10+1 = [0]+1 = 1
Botch Check: 1D10 = [4] = 4
:mrgreen:
PeVi15 Thwarting the Thaumaturgical Threat!
Stamina +1, Perdo 5, Vim 5, Mastery 3, Aura 3, Tired -3, Fast Casting -10, equals 4 plus a die roll
Counterspell!: 1D10+4 = [5]+6 = 9
With Stalwart Mastery, no Fatigue is lost 
Now, according to the mechanics for this spell, Roberto rolls a Stress Die plus (the level of this spell +10), against an Ease Factor of twice the level of the effects (unknown). So that starts at +25. Untravelling Mastery adds three times the Mastery score to the roll, so that is another nine for +34. Then he is tired -3, for a total of 31 plus a die roll.
Thwart Roll: 1D10+31 = [6]+31 = 37, so that counters level 18 or better.
Fast Cast again!
Quick +1, Finesse 3, Tired -3, Second Fast Cast -6, equals a die roll minus 5
_: 1D10 = [4]-5 = -1
Which still beats Attuma's -9
:mrgreen:
Getting desperate here
Not a counterspell. Going to try a PoF and pray I roll really good for damage
Sta +1, Creo 6+3, Ignem 12+3, Mastery 4, Aura +3, Tired -3, Fast Cats -10, equals 19 plus a die roll...
PoF: 1D10 = [9] =9+19 = 28
Minus Level 20 equal 8, plus the Penetration super multiplier for his blood
Damage equals a die roll, +15, minus 5, or SD+10
1D10 = [1] = 1
exploder: 1D10 = [10] = 10
For +30 Damage total
And it's still not enough. The attack probably didn't kill him, the counterspell probably didn't work, and the PoF did no better than the attack. But I hope he botches his soke roll again
Another Fast Cast Spell!
Fast Cast Speed Quick +1, Finesse 3, Tired -3, Third Fast Cast -12, for a total of a roll minus 11.
_: 1D10 = [5] = 5
Equals -6! Still beats Attuma!
:mrgreen:
A Fast Cast Spontaneous Defense. I am going to just guess the Form is Aquam and pray this works.
Creo/Rego Ignem to boil away the water as it attacks me.
Stamina +2, Creo 6+3, Ignem 12+3, Aura 3, Tired -3, Fast Cast -10, equals 16 plus a die roll
1D10-11 = [1]
exploder: 1D10 = [1] = 1
exploder: 1D10 = [4] = 4
for sixteen plus sixteen, or 32, divided in half is sixteen. Enough to defend against level 32 or cancel level 16
Can he do it again? One more time?
Fast Cast Speed Quick +1, Finesse 3, Dazed -5, Fourth Fast Cast -18, for a total of a roll minus 19.
_: 1D10 = [6] = 6
For a -13
noooooooooooo!