Creature tokens you control have
trainingTraining is a triggered ability. “Training” means “Whenever this creature and at least one other creature with power greater than this creature’s power attack, put a +1/+1 counter on this creature.”
If a creature has multiple instances of training, each triggers separately.
Some creatures with training have abilities that trigger when they train. “When this creature trains” means “When a resolving training ability puts one or more +1/+1 counters on this creature.” (CR 702.149). (Whenever a creature token you control attacks with another creature with greater power, 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 that token.)
Blind Betrayal —
SacrificeTo sacrifice a permanent, its controller moves it from the battlefield directly to its owner’s graveyard. A player can’t sacrifice something that isn’t a permanent, or something that’s a permanent they don’t control. Sacrificing a permanent doesn’t destroy it, so regeneration or other effects that replace destruction can’t affect this action. (CR 701.21) another creature: Elder Arthur Maxson gains
indestructibleIndestructible is a static ability.
A permanent with indestructible can’t be destroyed. Such permanents aren’t destroyed by lethal damage, and they ignore the state-based action that checks for lethal damage (see rule 704.5g).
Multiple instances of indestructible on the same permanent are redundant. (CR 702.12) until end of turn.