DethroneDethrone is a triggered ability. “Dethrone” means “Whenever this creature attacks the player with the most life or tied for most life, put a +1/+1 counter on this creature.”
If a creature has multiple instances of dethrone, each triggers separately. (CR 702.105) (Whenever this creature attacks the player with the most life or tied for most life, put a +1/+1
counterTo counter a spell or ability is to cancel it: remove it from the stack without resolving it. A counter on an object or player is instead a marker that changes characteristics or interacts with rules or abilities; for example, a +1/+1 counter modifies a creature’s power and toughness. (CR 701.6; 122.1) on it.)
This creature can't be blocked by creatures with power 2 or less.
Whenever this creature deals combat damage to a player or
diesIs put into a graveyard from the battlefield. (CR 700.4),
proliferateTo proliferate means to choose any number of permanents and/or players that have a counter, then give each one additional counter of each kind that permanent or player already has.
In a Two-Headed Giant game, poison counters are shared by the team. If more than one player on a team is chosen this way, only one of those players can be given an additional poison counter. The player who proliferates chooses which player that is. See rule 810, “Two-Headed Giant Variant.” (CR 701.34).