Morning Star has 7 for 5 :
.
Immaterial on-play is worth a +1 value for weapons. (8 base ATK for a 'prototype Mercy')
Damage cap acts like a requirement for 1 extra card to maximize this card's damage. Most players will run Short/Long Sword for this purpose (1 | 1
, which basically means nothing ATM but it does mean -5 / -2 DMG with a prototype Mercy)
Morning Star takes 14 /13 turns to kill an opponent by itself for 5
+1 Card.
Prototype Mercy takes 8 turns to get down to 40 HP, and then Long Sword takes 7 more turns to get that HP down to zero for 5 | 4
+ 1
+ 2 Cards. (15 turns)
(Mercy + Long Sword should be at least 1-2 turns ahead of an (upgraded) Morning Glory given the two-card requirement and lack of PC protection.)
1st Change : Lower Damage cap to 30.
Morning Star/Glory takes 14 /13 turns to kill an opponent by itself for 5
+1 Card.
Prototype Mercy takes 9 turns to get down to 30 HP, and then Long Sword takes 5 more turns to get that HP down to zero for 5 | 4
+ 1
+ 2 Cards. (14 turns)
2nd Change : Raise Prototype's damage to 12.
Morning Star/Glory takes 14 /13 turns to kill an opponent by itself for 5
+1 Card.
Prototype Mercy takes 6 turns to get down to 30 HP, and then Short Sword takes 10 turns to get that HP down to zero for or 5
+ 1
+ 2 Cards. (16 turns)
Prototype Mercy takes 6 turns to get down to 30 HP, and then Long Sword takes 5 more turns to get that HP down to zero for 4
+ 1
+ 2 Cards. (11 turns)