No, because the life point payment effect is a Trigger, triggered by its summon. When summoned, you choose whether or not to use that triggered effect, and that's the only time you can do it.
If you choose to activate the trigger, you pay your life down to 100, so probably won't be able to activate the destruction effect unless you gain some life.
If you choose not to activate it, then you can activate his destruction Ignition Effect instead. However you've passed the timing for activating the ATK gain trigger, so you can't activate it after.
No. As long as the monster is in Defense position, White Ninja will destroy the target monster. So if Medusa worm was flipped face-down again by its effect, then yes, but if it is still in attack position, then no.
If this card attacks a defense position monster your opponent controls, destroy all defense position monsters your opponent controls after damage calculation. During your end phase, destroy all of your monsters that did not declare an attack this turn.
If the attacking monster has lower ATK than the defence-position defender's DEF, then the defender is not destroyed at all. What will happen is the attacking player will take damage equal to the difference between the attacker's ATK and the defender's DEF, but neither monster will be destroyed.
No. When a monster you control attacks a monster with a Defense higher then the Attack of your monster, you take damage equal to the difference but neither monster is destroyed. The only exception is due to card effects such as Des Kangaroo.
If the attacking monster is switched into Defence position, the attack ends. Damage Calculation is not entered, you do not compare the monsters' ATK or DEF.
he wants to escape the consequences of his choices
You cannot tribute summon a monster in face up defense position. You can either tribute summon a monster in face down defense or face up attack position. If you want to summon in face up defense, you need to special summon.
You put a monster in face down defense position BUT your not allowed to normel summon a monster in defense postion.
1 Tuner + 1 or more non-Tuner monsters If this card attacks a Defense Position monster your opponent controls, destroy all Defense Position monsters your opponent controls after damage calculation. During your End Phase, destroy all other monsters you control that did not declare an attack this turn.
Yes. If you hit a monster with higher defense than your attack, your attacking monster isn't destroyed, but you take damage. If the defending monster's defense is lower than your attack, then the defending monster is destroyed, but the defending player takes no damage, unless through an effect like "Dragon's Rage" or "Elemental Hero Flame Wingman"
You get to be gigantic and destroy man kind! What's not to love about being a monster?
An Egyptian monster who want the destroy the world