This is way better than the skill. Sure both players get to use it with is bad but let's look at pros and cons
3SD
Pros- doesn't require a card to summon lvl 5-7
CONS-
1. can't summon lvl 8 plus
2. Requires 3000 life points per activation
3. Reduces the monsters lvl to 4 for the turn( 4 star ladybug)
Masoleum of the emperor
PROS-1. can summon lvl 8+
2. Needs a Max of 2k life to summon
3 life point cost scales allowing you to summon lvl 5&6 for cheaper
3 doesn't change lvl so can use things like champion vigilance on turn you summon
CON
1 requires you to have masoleum out to summon
2 weak to s/t removal